After finishing the headlights in Electrical 7: Headlights it was time to track down why the heater blower motor wasn’t working. The symptom was a blown fuse as soon as I pressed any of the heater buttons. No power means the motor doesn’t work.
After changing several fuses I confirmed that the problem was in the blower circuit. It looked like something was creating a dead short. This could be from the new wiring harness, or I could have pinched something when re-installing the heater plenum.
The speed control for the blower motor goes through a big resistor mounted on the firewall in the engine bay. I started the underhood troubleshooting by unplugging one of the wires from the resistor.
Umm, why does this wire say NEUTRAL SAFETY SWITCH???
Krud. In the new wiring harness both of the wires for the blower resistor plus the wire for the neutral safety switch are all brown and come out of the wiring harness at the same location and have the same connectors on the end.
This is why it is critical to READ THE FREAKING LABEL (RTFL) when you are connecting devices!
Yup, the wire connected to the neutral safety switch says HEATER BLOWER MOTOR.
Connect the wire labeled NEUTRAL SAFETY SWITCH to the neutral safety switch. Now plug the wire labeled blower motor into the blower resistor. Hmm, its a bit too short. OK, wire up an extension with a new plug and plug it it.
Now to check the blower motor: No blown fuse! And the heater blower runs at low, medium, and high speeds. There wasn’t any rejoicing this time – I was too annoyed with myself for making such a stupid mistake.
The last thing was to try to start the car and make sure the neutral safety switch still worked. The Imperial fired up immediately, so that part is still good.
All that work labeling all the wires and then I don’t pay enough attention when actually hooking everything up. At least the problem was obvious when I finally looked. Grumble.
On a side note: If you are going to be doing a lot of electrical work it is a good idea to buy fuses in bulk. The retail price of automotive fuses can be over $1.00 each. Or you can get them for less than a dime by ordering 50 or a hundred at a time – for example, 20 amp mini fuses for eight cents apiece. Since it is easy to go through several fuses when tracking down a problem (at least for me…) it is good to have a box full of fuses available.
The next job is to figure out why the alternator isn’t charging.
After much discussion the time came to properly heat and cool the workshop. I’ve spent the last couple of years researching the options and concluded that the best solution was a mini split heat pump.
Mini Split Inside Unit
Mini splits are known for air conditioning. They also serve as heat pumps, down to ~30 degrees. There are models of mini splits that function as effective heat pumps down to 0 degrees – some even work as low as -15 degrees! These special mini splits are known as hyper heat, which was the name Mitsubishi applied to their pioneering low temperature units a number of years ago.
So we asked for a quote from Northboro Oil. We’ve been doing business with them for over 30 years, always receiving excellent service. We had them install our central AC 12 years ago, and our only complaint there is that we didn’t do it 25 years ago!
Paul came out, checked the workshop, and listened to what we wanted. We received a quote which was, as expected, expensive. My research showed that the vast majority of problems with mini splits were installation related. Our experience with Northboro Oil is that they do good work and don’t cut corners, which is what we wanted.
The quote was for a Fujitsu Halcyon AOUG15LZAH outdoor unit and ASUG15LZAH indoor unit. This is rated to heat down to -15 outdoor temperature, which should be fine since our area very rarely goes below 0 and is usually 10-30 degrees in the winter. Fujitsu is one of the top three makers of mini splits, so the quality and longevity of this unit should be good.
At 15,000 BTU cooling this unit is smaller than I expected – I had been looking at either an 18,000 or a 24,000 BTU unit. Actual heat calculations showed a cooling requirement of 8,000 BTU based on the design and insulation of the workshop. The biggest concern was whether or not the 15,000 BTU unit could ramp down enough for effective de-humidification. Not the outcome I expected!
There were some concerns about heating capacity, as this unit looked marginal. This was based on keeping an indoor temperature of 70 degrees on a 2 degree day. My needs are closer to an indoor temp of 60 on a 10 degree day, which produces an answer of “OK, its fine then.” The old electric heater is still hanging from the ceiling as backup/booster; it might as well stay there until I need 220V service in that corner of the workshop.
I called them on Monday to accept the quote and see about scheduling installation. The date was set for two weeks out. This was a pleasant surprise – I had been hoping for a month and wouldn’t have been surprised at 2-3 months. Things were looking good!
The next morning I got an 8:00am call from Northboro Oil: “A job we had scheduled for today isn’t ready. Can we install your mini split starting at 9:00am today?”
Umm, yes?
The crew showed up at 9:00 am and had most of the work done by 5:00pm. They came back Wednesday morning and had all of the mechanical work finished by noon. This included leak test by pressurizing the system to 400 psi with nitrogen and waiting an hour to see if the pressure dropped. This was followed by a vacuum pump to remove all air and moisture from the lines and then waiting another hour to see if the system held vacuum. Both of these were successful, so the valves on the indoor and outdoor units were opened allowing the Freon to flow through the system. Well, it is actually R410A, not Freon, but you get the idea. The only thing standing in the way of cool air was electrical power!
The electrician came by in the afternoon to scope out the electrical work.
The electricians showed up at 9:00am Thursday and left by 9:45. This included time spent discussing the Imperial and the workshop…
I had done all of the rough wiring for the AC before insulation and sheetrock. This included the 220V AC Disconnect and the required 120V service outlet on the outside back wall of the shop. All the electricians had to do was run a waterproof whip from the AC Disconnect to the mini split, swap out the 30 amp breaker for a 20 amp breaker, and connect the 4 wire control cable between the indoor and outdoor units of the mini split. The electricians were quite happy with me, saying “you did all the hard work for us!”
I thought about doing the electrical myself, but ultimately decided to have them do it. If there are any problems they own the whole thing and there aren’t any questions.
Mini Split Outside Unit. The stand keeps it out of the snow in winter.
Of course we are now having mild weather, with temperatures in the mid 70’s, making it difficult to really try out the AC. The inside temperature of the workshop is 75 and the Imperial, fresh from a 70 mile run, is parked inside with the 413 radiating heat. The thermostat is turned down to 68 and the temperature is dropping.
Both the indoor and outdoor units are virtually silent – to the point that I can’t tell if they are running unless I walk up to them. I think I’m going to like this setup!
Update:
Day 2 of a heatwave. 95 degrees outside, 71 degrees inside. I can live with this!
When we last saw the Imperial it was running great on a short test drive. It was now time for a serious drive!
I started out slowly, driving around the block while watching the gauges and paying close attention to any possible signs of problems. So far everything was going great…
Next step was to drive some back roads. Still the same, everything was working great. OK, time to live dangerously, so I headed for the Interstate.
This time the Imperial pulled onto the Interstate with plenty of smooth power – no signs of hesitation or loss of power. This car likes the Interstate. I ended up putting 70 miles on the car today, mostly cruising at 65-75 mph keeping up with traffic.
The car rides smoothly and tracks straight. It is fairly quite, with most of the noise coming from wind. This was expected, as it needs new door gaskets and window gaskets. New gaskets will be installed after bodywork is done and it is painted.
Even better, the gas gauge works! It started on full, and then went down at what looked like a reasonable rate. On the way back home the gauge was showing just under 3/4 of a tank when I stopped for gas. Filling the tank took 8 gallons. With a 23 gallon tank, just under 3/4 of a tank should be 7 gallons if the tank and gauge worked perfectly. Considering that a fillup may fill the tank over its rated capacity, this is a near perfect result. I still want to check calibration at a half tank and quarter tank, but things are looking good!
Even better – gas mileage was 11.1 mpg! After a 1,000 mile break in period I will probably be getting around 12 mpg on the highway. While horrible by any sane standard this is still good gas mileage for this kind of car.
The test drive wasn’t perfect. The alternator may not be charging correctly; I need to look into that. The temperature gauge is still reading warm, not hot, but warm. This also needs more research.
Electrical 6: I Need Power! described the installation of the new fuse/relay box and rough wiring. The next step was to complete the headlight wiring by installing a Weather Pack 4 pin connector on the new wiring harness.
I may have slightly overstated the status of the headlight wiring… While the new wiring is indeed 12ga, it doesn’t run all the way to the headlights. There is a separate run of wire from the main harness to the headlights. Recall that one of the defining features of 1961-1963 Imperials is the podded headlights.
1963 Imperial Headlights1963 Imperial Headlights side view
The wiring runs up from the bottom of the headlight through the base, into the pod, and then through a connecting bar between the two pods. There is minimal space for the wiring – getting four 12ga wires in here will be a real challenge. So I decided to punt on this for the moment by re-using the existing headlight wiring and building an adapter between the new wiring harness and the existing headlight wiring. The headlight wiring will be updated when I have the headlights out for painting or when I send them out to be re-chromed.
While re-using the existing 16ga three wire setup isn’t ideal, the remaining 16ga wire is short and the upgrades to the rest of the system help a lot.
The existing headlight connector is a 3 pin Packard 56 connector. Of course I have 1 and 2 pin Packard 56 connectors, but no 3 pin. Not a problem – cut the existing connectors off of the old wiring harness leaving a 3″ pigtail. Then crimp Weather Pack connectors onto the ends of the old wires and install in the mating shell for the new wiring harness. As long as everything is opened up, go ahead and spray the old connectors with contact cleaner. Viola, or maybe even voila, and the headlights are plugged in and working.
Headlight connector (bottom connector)
In this picture you can see the four 12ga wires of the new harness going into the sealed Weather Pack connector, the three 16ga wires from the original harness, the the three wires going to the headlight. Also shown are the green and yellow wires to the parking and turn signal lights.
The headlights are now substantially brighter than they were before. Thanks to the relays and new wiring I no longer have to worry about the old wiring or the old headlight and dimmer switches. The headlights had already been upgraded from the really old incandescent bulbs to the somewhat less old sealed beam halogens. A planned upgrade is to replace these with modern H1/H4 lights – this will probably be done when the headlight pods are rewired.
A couple of other notes on the headlight wiring: 35 amp relays were used; this makes sure that the relay is not the weak point of the system. Even using 65 watt bulbs, the four high beam headlights will only be pulling a total of 20 amps. 100 watt HI beams could be a problem, but even then they could be split across two relays. And 100 watt bulbs would probably melt the pods!
This particular Bussmann fuse/relay box was chosen because it supports circuit breakers as well as fuses. The headlights will use these automatic resetting circuit breakers for maximum reliability and safety.
Next: is the Imperial ready for the road? Find out in Cruisin’!
As described in the previous article Towed the Imperial is waiting for parts. Which means that it is a good time to get back to the electrical work last seen in Electrical 5: Boxing. With the location and mounting of the new fusebox resolved the next step is to fill up the fusebox.
The plan is to completely replace the existing under hood wiring harness with all new wires. Everything from the new bulkhead connector forward is being replaced – and upgraded. In addition to installing new wires, I’m increasing the size of the wires: 18ga is replaced with 16ga, 16ga is replaced with 14ga, 14ga is replaced with 12ga, and 12ga is replaced with 10ga. This is probably overkill, but there is very little cost difference in going one size larger on wire.
The process for building the new harness is straightforward. It is also time consuming and tedious…
To start, mount the new fusebox and measure the distance from the bulkhead connector on the firewall to the fusebox. This is the length of the new wires to the fusebox. As this will ultimately be a large stiff bundle of wires it is critical to get the length right.
Remove the new fusebox and take it over to the workbench. Dig out the carefully planned wiring diagrams that show where everything will be connected in the fusebox and how the wires are arranged in the bulkhead connector.
Workbench with new wiring harness, old wiring harness, and tools
The new Bussman 15303 fuse/relay box has two power busses. One bus is used to provide all power – it supports 10 fuses and is rated at 80 amps which should be more that adequate. The other bus is used to ground pin 85 on the relays; this is a low power application, but simplifies wiring.
Wiring the relays requires four connections: power, load, signal, and ground. Power goes from the power busbar through a fuse to the power side of the relay and then from the load side of the relay to where it is being used. The original power for each circuit is now used merely as a signal to the relay.
The first step is to wire a 12ga jumper from a fuse to the power side of the relay (pin 87) for all five relays. Wiring it this way means that the relay is protected by the fuse. Since the relays are the most complex part of the new harness they are wired first. The Bussmann box has considerable flexibility and can be wired with or without relays.
The original headlight wiring is a joke. Power for all four high beams was run through a single 16ga wire. A long run of 16ga wire, going through the headlight switch. Even if this were capable of safely carrying the current, the voltage drop through this tiny wire greatly reduces the brightness of the headlights. According to Danial Stern Lighting a 1 volt drop reduces light output 30% – going from the rated 12.8V to 11.5V reduces a 1,000 lumen headlight to 693 lumens. Going down to 10.5V takes the headlights down to a mere 510 lumen – a loss of 1/2 of available light!
The original headlights were 35 watts. Running the 4 Hi beams would be 140 watts or 11 amps. New headlights typically draw 55 watts or higher, with 65 watt high performance bulbs readily available. The headlight system needs to be designed to handle 260 watts with minimal voltage drop. And without burning up the headlight switch – at 12.8V, 260 watts is over 20 amps! 16ga wire is rated for 10 amps, meaning that it is marginal for the original bulbs and too small for modern bulbs.
The new design uses relays with a dedicated wire directly from the relay to each headlight. The original plan was to also have a dedicated ground for each headlight, which would require five wires to each side (two headlights per side): hi beam 1, hi beam 2, low beam, ground 1 and ground 2. A four wire connector is easier to fit through the holes, so the design was modified to hi beam 1, hi beam 2, low beam, and ground. To compensate for this the ground wire is now 12ga for two headlights instead of 16ga for four headlights.
14ga wire is plenty to power the headlights, especially with the short run from the relay to the headlights. Looking through my wire supply turned up longer rolls of 12ga than 14ga. OK, overkill it is – 12ga for all the headlights!
Time to start wiring. The old wiring harness was placed on the workbench next to the new fusebox as a reference. Using the low beam headlights as an example: The low beam is identified as circuit L-4, a black wire installed in pin C of the bulkhead connector.
Since this is now just a signal wire, a piece of 16ga black wire is cut to the length previously measured from the new fuse box to the bulkhead and labeled (with shrinkwrap labels) as “L-4 LO BEAM”. Actually, this wire is cut a few inches long; we will trim all wires going into the bulkhead to the same length at a later stage. A MetriPack 280 connector is installed on one end and plugged into the fusebox on pin 86 of relay 1. The wire is routed out of the fusebox where it will later be gathered into a bundle.
Next, go to the old harness and measure from the location of the fusebox to the left side headlight connector. Cut a black 12ga wire to this length and label each end “L-4 LO BEAM 1”. Cut a white 12ga wire to the same length and label each end “HDLT GRND 1”. Might as well take care of the HI beams at the same time, so measure and cut two pieces of red 12ga wire and label them “L-3 HI BEAM 1″ and L-3 HI BEAM 2”.
Since there are four headlights on the car, measure the length to the right side headlights and cut and label the four wires.
For the Low beams there are two wires going to the relay. Using a heavy duty butt crimp connector, the two wires are stripped, wrapped together, and crimped into one side of the connector. A short 12ga jumper wire is crimped to the other side of the butt connector and the whole thing is sealed with marine grade heat shrink tubing. A MetriPack 280 connector is crimped onto the jumper wire and plugged into pin 87 on relay 1.
The Hi beams are done the same way. You can’t run four 12ga wires into a butt connector, so a small weather proof buss bar is used instead.
A grounding buss is mounted inside the mounting box for the fuse box. The headlight grounds and relay ground are connected, along with a 10ga wire going to the chassis ground bolt.
One challenge with upgrading power is that the Weather Pack bulkhead connector only supports 20 amps per pin. Of course this implies that two pins will support 40 amps… So, run two wires with 20 amp fuses from the new fuse box to the bulkhead. On the inside, run two wires from the bulkhead connector to the unswitched power buss on the interior fusebox. Bingo, 40 amps of power is now available from the fusebox!
Switched power is done the same way using two relays. The ignition circuit, J-2, which provides power to the ignition coil, is live whenever the car is turned on. This circuit is tapped to provide a signal to relays 3 and 4. These relays are connected to the bulkhead connector, providing 40 amps of switched power to the interior fusebox.
One of the side effects of being forced to remove the AutoPilot cruise control is that the three control wires for cruise control are no longer needed and could be removed from the bulkhead connector. This made it possible to directly connect the power seat and power windows directly to the new fuse box. I had previously added a MetriPack 280 connector to these circuits. New wires were run from this connector to the bulkhead, and new wires run from the bulkhead to the new fuse box. The result is that power for these high current devices now comes directly from the new wiring.
This takes care of the power circuits. There are also several other wires going through this part of the harness, such as side marker and turn signals, horn, and windshield washer. These wires are traced and a new wire is cut to length, labeled, and routed through the fuse box.
After checking and double checking that all wires for this part of the harness have been added it is time to sleeve the wire bundles using braided sleeve. The wire bundle is run through the appropriate size sleeve and the ends of the sleeve secured with heat shrink tubing or electrical tape. Both wire bundles going into the fuse box are quite large – they barely fit through the 1″ grommets in the box.
Finished fuse/relay box
After sleeving the wires the connectors are added. The bundle going to the bulkhead connector is straightened out and all the wires cut to the same length. Weather Pack connectors are crimped onto the ends of each of these wires.
It is finally time to start updating the bulkhead connector. A circuit from the new fuse box is chosen such as L-4 LO BEAM. The pin for this circuit in the bulkhead connector is identified and removed using a Weather Pack pin removal tool. The new pin from the new fuse box is inserted into the bulkhead connector and locked in place. Finally, a piece of yellow masking tape is placed on the old pin – this lets me know that I have finished working on this circuit. As I may have mentioned, I get confused easily and there are 22 pins in the bulkhead…
After connecting all the wires going to the new fuse box it is time to answer the most important question: did I cut the wires too short? The bulkhead and the new fuse box mounting are fixed, and the wiring bundle is short, stiff, and has no give. If these wires are short I will have to go back to ground zero and start over again. No pressure…
The whole bundle of new harness and old harness are picked up and the new fuse box is mounted in place. Go to connect the bulkhead connector:
And the wire bundle is 1″ too long. Perfect! Absolutely perfect! This is just the length needed to provide a little bit of give in the bundle so it can be arranged out of the way, makes it easy to connect, and isn’t long enough to cause other problems. And there was much rejoicing!
Fuse/relay box connected to Bulkhead
Remaining steps include finishing the headlights, turn signals, parking lights, horn and windshield washer. After that is wiring the engine, including ignition, HVAC, and sensors. Last is doing the new wiring for the Alternator.
Not a great day – the Imperial died in the middle of a test drive and had to be towed home.
As a break from the electrical work covered in Electrical 5: Boxing I had decided to put some miles on the car to break in the engine and suspension and to try to work out a problem with losing power under acceleration. Bad idea! The loss of power got steadily worse, ultimately stopping completely in the middle of the road. Fortunately I had gotten off the Interstate and was looking for a place to park. Unfortunately I hadn’t found that place when it quit completely.
Fortunately a kind gentlemen in a pickup truck (hi, Ken!) stopped and asked if I needed help getting towed off the road. He hooked up a tow strap and pulled me 1/4 mile over the top of the hill and into the parking lot of Westward Orchards in Harvard.
Sitting in the parking lot at Westward Orchards in Harvard, MA
First things first, so I headed in to the store, bought a coffee, told them I had broken down, and asked if it was OK to stay in the parking lot for a while. “No problem!” was the answer – this was a case where it was better to ask permission than forgiveness. OK, this was actually the second thing – the first thing was thanking Ken profusely for his help!
There wasn’t a trace of gas in the fuel filter – bone dry. This confirmed my suspicions of a fuel delivery problem. Looks like a blockage in the lines or a bad fuel pump. Or maybe air leaking into the lines. Nothing that can be fixed in the parking lot, so time to call for a tow. Thanks to the miracle of cell phones this is easier than it used to be. Fortunately it only took 45 minutes for the tow truck to show up, and a half hour later the Imperial was back home.
Blocked lines don’t make any sense – the fuel tank, fuel sender, fuel lines, fuel filter, and fuel pump are all new and were working up to this point. The fuel pump is brand new with less than 100 miles on it, but it is the most likely suspect.
NAPA didn’t have any of these fuel pumps in stock, so I had to order a new fuel pump. While waiting I dug out the original fuel pump and installed it. I had replaced the original pump to avoid problems like this from happening…
With the original fuel pump back in place – nothing. Not a drop of gas. Stubbornly remains bone dry. Krud.
OK, time to troubleshoot the entire fuel system checking for blockage or leaks. All of the lines are clean, all of the connections are tight, the fuel hoses are securely clamped to their fittings, and the fuel tank vent is fine. Blowing air through the lines showed that they are open with no trace of blockage. In fact, after I removed the input line from the fuel pump gasoline continued to dribble out of the line, siphoning from the gas tank. Clearly gas is getting to the fuel pump. The fuel filter and lines to the carburetor were checked and were also open.
Once again the evidence is pointing to the fuel pump. And I have another new pump on order. But this still doesn’t make sense – failure of two pumps that were working is unlikely…
Sigh. More diagnostic work is needed. I’ll update the Blog when I find something.
Update (12July2021)
Some online research revealed that a common problem is wear of the pushrod that goes between the camshaft and the fuel pump. This pushrod connects the fuel pump lobe on the cam to the pump lever in the fuel pump.
Fuel Pump and Pushrod
The pushrod is supposed to be 3.22″ long. It is fairly easy to remove – remove the fuel pump, unscrew the retaining plug, and the pushrod drops out. OK, it drops out after grabbing it with needle nose pliers and wiggling it a bit…
Fuel Pump Pushrod Length
Fire up the trusty digital calipers and measure the length: 2.942″. The pushrod has worn 0.278″ – over a quarter inch of wear! You can easily see the wear – there is a thicker section in the middle of the pushrod that rides in the bore and reduced sections at each end. These end sections should be the same length. You can clearly see that the right side is shorter than the left side. You can also see some wear toward the right side of the middle section.
There is no way the fuel pump could work with this much wear – it is amazing that it worked at all! The pushrod should have been replaced when the engine was rebuilt; I’m disappointed the shop didn’t do that. If I ever rebuild another Chrysler big block I will know to check the pushrod while the engine is out of the car. Or better yet just replace it as another wear part in the engine.
A new pushrod is on order. Hopefully this is the only problem; wear on the camshaft would be really bad. Will update again after the new pushrod is installed.
Update 2: 29July2021
After a bit of a comedy of errors (my errors…) the new fuel pump finally pushrod showed up. Installation of the pushrod and fuel pump was actually quite easy. Then the moment of truth:
Crank the engine over for several seconds. Go to check the fuel filter. And there was gasoline in the fuel filter! Crank the engine some more and it started and ran. And there was much rejoicing!
At this point I changed the oil and filter in case there was any metal from the pushrod in the oil.
Fired the engine up and drove the car around the block a couple of times. It is running great! Running smoothly, plenty of power, and no hesitation. I had other commitments and couldn’t spend much time driving the car, so putting some quality miles on it will have to wait for another day.
On another note, all of the electrical wiring is working (see the thread on Electrical for details). This is a pleasant surprise, as I had expected to have to track down and fix at least a few mistakes.
After Retiring the Imperial it was time to get back to electrical work. Electrical 4: Modernizing the Fusebox covered updating the old fusebox under the dash. I’m now at the point where I can start working on adding a high power fuse/relay box in the engine bay that will both completely bypass existing wiring for high current devices as well as provide more power for the upgraded interior fusebox.
The fuse/relay box used was a Bussmann 15303 which provides five relays and ten circuits protected by fuse or circuit breaker. It is a weatherproof box which uses MetriPack 280 terminals and includes two 100amp internal buss bars.
Bussmann 15303 Fuse/Relay box
Since the new fuse/relay box is roughly the size of the already removed AutoPilot, the plan was to install it where the AutoPilot used to be. Unfortunately you can’t just “put the fuse/relay box under the hood” – you need something to hold in in place: a bracket!
I had done a simple bracket for the interior fusebox, which I wasn’t completely happy with. The Bussmann box requires a fairly complex cut-out which I had done by hand. Crudely. You can’t see it under the dash, but the under hood location will be more visible. In addition, the under dash bracket was a simple bent flat sheet, while the new bracket really needed to be a box. Not only that, but a box that serves several purposes beyond simply holding the Bussman 15303.
As part of my tremendously successful ongoing program of making simple tasks complex, I decided to design the bracket as a 3D Solid Model using the Autodesk Fusion 360 CAD program, unfold the 3D part into a 2D flat pattern using the Fusion 360 Flat Pattern module, and have it laser cut from steel by Send Cut Send. This is in contrast to the Cardboard Aided Design and hand grinder with cutting disk approach which is commonly used to design brackets.
Many years ago (I decline to say how many…) I was a Computer Aided Design – CAD – expert. I designed jet fighters (OK, I was a junior engineer on an 8,000 person design team) using a state of the art CAD system to design complex parts, mostly in sheet metal and composites. It has been years since I did any CAD work and I wanted to get back into it using the latest technology.
Fusion 360 is an incredibly powerful Solid Model based design and drafting system which is currently available to hobbyist under a one year zero dollar license – in other words “free”. To summarize my view of Fusion 360: WOW! Where was this technology when I was designing things for a living? A couple of tiny nits: Fusion 360, like all powerful software, has a learning curve. Solid modeling is very different from the wire frame based systems I learned on. And I’ve forgotten most of what I used to know…
After a few weeks of fighting Fusion 360 I had an initial design to be bolted to the inner fender:
Original bracket in Fusion 360
This design didn’t work – too big and there was no place to attach it to the fender. So, back to the “drawing board” and come up with a modified version:
Revised bracket design
It was incredibly simple (OK, simple the 5th time I tried to do it) to do this design in Fusion 360: Design the top surface with the cutout and then select an edge and specify how long this flange was. In the case of tabs on a flange, just select an edge of the flange and specify how long the tab was. These flanges could be edited, so I added 3/8″ holes to allow plug welding the flanges to the tabs after folding the metal part.
After completing the 3D design the 2D flat pattern was produced simply by picking the 3D model and executing a single Unfold command:
Flat Pattern with bend lines
With the design done it was time to send it out for fabrication. Send Cut Send is basically a “sheet metal print shop” which uses a laser cutter to cut precision parts out of steel, stainless steel, aluminum, copper, brass, titanium plastic, carbon fiber composite, wood, and other materials based on customer electronic design files. Sheet metal is a bit of a misnomer – they can cut metal up to 1/2″ thick! They can handle anything that can be cut out of flat stock, and are set up to produce from one to several thousand copies of a single part.
Send Cut Send has an interesting business model: they have a fully automated price quoting system to price per part with a $29 minimum order. They have fully automated all of their processes and they buy materials in large enough quantities that you can often get complete finished parts for less than what it would cost you to buy the raw materials!
I uploaded the flat pattern and started a new order specifying 22 gauge (0.030″ thick) steel. Hmm, the part is going to cost $9.37. I can order either one part or three parts for the same $29 minimum charge. Decisions, decisions… OK, three parts it is!
A few days later a package showed up with the parts ready to bend up.
Sheet metal flat patterns from SendCutSend
With three parts I could afford to screw up two, so I grabbed the top part and started building up a prototype. First, bend the flat parts into the final box:
Folded Fuse/Relay box
“Plug weld” means welding through a hole to the metal behind it, and is a powerful tool for working with sheet metal. I forgot to turn on the gas in the MIG welder for the welds on the right – they are complete garbage. The welds on the left, with gas, are much closer to what they should be.
There were many details to work out on how and exactly where to mount the box, wire routing, and grounding. Mistakes were made — I mean “several options were explored in order to determine the best final approach”.
That description is way to simple. The reality was THE BLOODY BOX DIDN’T FIT NO MATTER WHERE I TRIED TO PUT IT! No matter what I tried, something was in the way! <Calm down, calm down…> The engine bay of the Imperial is surprisingly small. The area where I needed to put the box in was cris-crossed with lines, hoses, wires, boxes, and assorted parts. Not to mention THE FREAKING HOOD HINGE WHICH LOOKS LIKE IT IS OUT OF THE WAY UNTIL YOU TRY TO CLOSE THE FREAKING HOOD.
Ahem. After trying many different approaches I finally succeeded in finding a location that would work and built additional mounting brackets to actually support the box.
Finished fuse/Relay box wired and installed
After getting something I was happy with the good elements were transferred to the second part which was then folded, welded (this time with gas), finished, and painted. Here is the finished mounting box with the fuse/relay box installed:
Fuse/Relay test assembly
Next: it’s not a good day when you have to be Towed.
In Sounds of Silence we made tremendous progress on the interior – but weren’t quite ready to really drive the car.
I didn’t trust the tires that came with the car. They weren’t the right size for the car, were who knows how old, were rather worn, and two of them had slow leaks. Not confidence inspiring for running a 5,000 lb. behemoth down the Interstate! Or for driving on twisty New England roads.
With the Imperial ready to go, it was time for new shoes. The Imperial came with 8.20 x 15 tires. This is an obsolete size, which was replaced by L78-15 (not an exact fit) and later by modern metric size tires.
Somewhat surprisingly the original 8.20 x 15 tires are now available, even in the original whitewall. This wasn’t the case a few years ago. Companies like Coker Tire offer tires such as American Classic Radial that is basically an improved version of the original factory tires. They also offer bias ply tires which are the same as the original factory tires and offer a factory experience including a smooth supple ride, poor handling, and rapid tread wear. The bias look radials are expensive.
I’m planning on taking some long trips in the Imperial, so a modern radial tire is attractive. The closest size is P235-75/15; this tire is ~3% smaller than the factory tire and has a wider footprint. Several companies make this tire. I’ve had good luck with Michelin, and ultimately decided on Michelin Defender LTX.
The Defender is designed for light trucks and SUVs, so it has the weight capacity for the Imperial. Today’s SUVs are basically luxury cars and expect a smooth and quiet ride, so this should work. Reviews of this tire indicated that it is quiet and has a good ride, as well as good ratings for traction on dry roads, in the rain, and in light snow. It is also half the price of the Coker radials. The Defender isn’t available in whitewall, but I can live with blackwall.
BJ’s had the tires on sale. As far as I can tell, BJ’s always has tires on sale… In any case the Imperial is now sitting on four new tires.
I’ve only had the chance to take a fairly brief test drive, but I think I’m going to like these tires. With the new suspension, new sway bars, and front end alignment, handling was already improved even with the old tires.
With the Michelins the handling is more positive. The tires respond more sharply to steering input, there is less roll in corners, and the overall feeling is more secure. The ride is quiet (thanks to all the sound insulation), and smooth. There is some roughness going over bumps, which I think is largely due to the new shock absorbers; will see how it feels after I have a few thousand miles on the car.
At this point I would say the work has turned out well. Changes include all new suspension parts, front disk brake conversion, heavier front sway bar, added a rear sway bar, rebuilt power steering box, new shock absorbers, and new tires.
Previously the car was scary to drive – leaning and lurching in the corners, vague steering feel, considerable roll when turning, pulling to one side when braking, and noisy. It now corners flatter, is smooth, doesn’t make noise, and brakes straight. It isn’t a sports car, but it is much more confident and comfortable to drive.
Imperials are known for being quiet. Mine wasn’t. It is now.
No carpet was big part of the problem, along with the removal of sound deadening undercoating described in Bottoms Down. While carpet is a good start, you can do much more. Of course you have to do this “much more” before installing carpet.
The first step is to remove the seats. The rear seats weren’t bad, but the front seat weighs 150-200 pounds and is awkward. Once again the engine hoist comes to the rescue – raise one end of the seat on the hoist and wrestle the other end. The hoist rolls as you move the seat, so this really wasn’t that bad.
Engine hoist used to remove front seat
With the seats out you can see how Chrysler used undercoating on the floors as well as the bottom of the car. Hmm, if it is on top of the floor is it undercoating or overcoating?
Front floor showing “overcoating” and wear
In any case the undercoating was thick under the seats and largely missing from the foot wells. Removing the overcoating wasn’t as bad as removing undercoating, but it still took me three days to get it removed and the floors cleaned. With the floors bare a coat of epoxy primer was brushed on – much neater and easier than trying to spray the inside of the car.
Front floor cleaned and ready for epoxy primer
There are two kinds of soundproofing materials used in cars – deadening and absorbing. Deadening is done by applying a heavy and viscous material that reduces vibration in metal panels. The original heavy undercoating did this as well as protected the bottom of the car from damage. Sound deadening can also be done with stick-on sheets of a heavy rubber mastic. The best known version of this is Dynamat, which is also one of the most expensive.
Digging around I found Noico which had good reviews and was about half the price of Dynamat. Most sound deadening material is .050-.067 inches thick, while Noico is .080. Since sound deadening effectiveness is related to thickness the Noico should be good. Two boxes are enough for most cars, so I ordered three boxes. It was almost exactly enough.
This material consists of three layers: embossed aluminum top layer, rubber mastic middle layer, and a peel off paper layer. You adjust and trim the material to fit, position it, and roll it down until the embossing in the aluminum is flat. A somewhat tedious job, but much better than working on the underside of the car!
There are differing views on how much coverage is needed. Some people claim 60% coverage provides most of the sound reduction. The manufacturers of the sound deadening material suggest getting as close to 100% coverage as possible. You can guess which way I went…
Installing sound deadening mats
The other type of sound deadening is absorption. This uses a heavy urethane foam that actually absorbs noise. It also insulates heat, making it desirable for the firewall and floors. And possibly for the roof; haven’t decided about that yet.
Noico also makes sound absorbing foam, which gets good reviews and is low cost. It comes in two thicknesses: 315 mil (thousandths of an inch) and 150 mil. I had one box of each; thought I ordered two boxes of 315? Oh well, 315 for the firewall and front floors and 150 for the back seat. This mistake turned our for the best – a box of 315 covers 20 sq. ft., while a box of 150 covers 36 sq. ft. 150 is easier to work with and I ended up with very little left over.
Installation of the foam goes much like the mat: trim to fit, remove the backing, and stick down. The big differences are that you don’t have to roll it and you have to position it right the first time – the adhesive sticks as soon as it touches down, and you tear the foam trying to remove it. 100% coverage is needed for the foam to provide effective insulation and sound deadening.
Carpet proved to be a challenge. There just isn’t much aftermarket support for these old Imperials. I found one place that had it listed in their catalog and ordered it. The order was cancelled two days later as the carpet was no longer available. Well, at least they didn’t drag it out for months…
More research turned up another place claiming to have Imperial carpet. I contacted them to ask if it was actually available. They checked with their supplier and answered “yes, it is available and has a 6 week lead time”. Sure enough, it showed up 6 weeks later.
The carpet was a decent but not great fit. It had some tailoring for the transmission tunnel but just didn’t fit like factory carpet would. I was able to adjust, tweak, and trim it to a usable configuration but there are still a few wrinkles. Realistically, no one will notice with a black carpet.
The front seatbelts were reinstalled and new rear seatbelts added.
Carpet, foam padding/insulation, and new seat belts
With the carpet in and all the trim pieces installed this job was done.
Carpet Done! Silver cutouts are for front seat tracks.
With the sound deadening and carpet done it was time to dig out the engine hoist and reinstall the front seat.
Carpet and seat done. Try to spot the wrinkles!
With everything back together it was time for a road test to determine if all this work was worthwhile. Short answer: Yes!
Yes, it was absolutely worth it. The car is MUCH quieter than it was before. To the point that driving it is a different experience. There is almost no road noise and engine and exhaust noise is greatly reduced.
I could do more. Sound deadening it the doors is supposed to make a significant difference, as is a hood pad. Sound deadening and insulation in the roof is also recommended, as is sound deadening and carpet for the trunk. But right now things are so much better that there is no sense of urgency for tackling these projects.
In an earlier article I claimed that the vacuum powered push/pull actuators for the heater air doors were working. This proved to be a bit optimistic… There was some movement from some of the actuators but the system didn’t seem to be working quite right.
I needed to do some serious diagnostics of the entire vacuum operated system. This would require running the engine for extended periods of time while connecting, disconnecting, and trying multiple components as well as trying to determine if there were any leaks. There had to be a better way…
Doing a search for vacuum pumps I discovered links to electric pumps for power brakes. These are used for things like cars with big cams which don’t produce much vacuum as well as hybrid and electric vehicles. Hmm, this could be a very useful tool for troubleshooting vacuum problems! And they aren’t that expensive – for example, this Viktor pump is less than $40. And it can be connected directly to the car battery. I learned that the vacuum pump has an unexpected feature: it shuts off when it reaches full vacuum. This proved to be a very powerful troubleshooting tool for detecting leaks. I discovered this when initially testing the pump with a vacuum gauge attached – the pump ran for a second and then stopped. I initially thought the pump was bad and then realized what was going on.
While considering different approaches to connecting to the car battery I realized that a portable power supply would be convenient. I’ve been considering getting a bench power supply for a while – these are useful for a variety of electrical projects as well as electrolytic derusting. So, add a Kungber 30V 10 amp power supply to the order.
Electric Vacuum Pump and Bench Power Supply. Apparently photographing black on black on black with a large white blob isn’t ideal…
Using this setup is simple and effective: remove one of the vacuum lines from an actuator, turn on the pump, and observe the result. Then connect the vacuum pump to the other side of the actuator and verify that it works in both directions.
Electric Vacuum Pump connected to Vacuum Actuator
Possible outcomes:
The pump runs, the actuator moves to the side the vacuum is connected to, and the pump stops when the actuator reaches its limit of travel. This is normal operation for a good actuator.
The pump runs and then stops but the actuator doesn’t move. The actuator is bad.
The pump runs, the actuator moves to the side the vacuum is connected to, the pump stops when the actuator reaches its limit of travel but then cycles on and off. This indicates a small vacuum leak. If the pump is cycling every 20-30 seconds, probably nothing to worry about. If it is cycling every 2-5 seconds, the actuator is a candidate for replacement.
The pump runs continuously without stopping. There is a significant leak in the actuator and it needs to be replaced.
There are four vacuum actuators in the Imperial. Two of these work, one works but the pump cycles on and off, and one doesn’t move even though the pump is running continuously – this one clearly has a large leak.. In addition, one of the actuator arms won’t stay on its air door, so a retainer clip is needed.
Of course replacement actuators aren’t readily available. The next project is to figure out how to replace or repair the bad actuator and decide whether the partially leaky one also needs to be replaced.
Introducing the Imperial Deathstar, a black 1963 Chrysler Imperial. This is one of the largest production sedans ever built, and arguably the best luxury car of its day.
Join me what will probably be a never-ending saga of grease, aching muscles, and an empty wallet as I work to restore this over 50 year old survivor to a reliable cruiser.
