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This may or may not work and it depends on other electrical items in the car and how the electrical system all ties together.

Most ignition switches have a contact inside only for the coil so that when the switch is turned off that contact is broken separately. That way the coil is isolated and it can not receive any feedback voltage and the engine will quit. If you tie the coil to the accessory post then depending on how the generator or other components are connected, the generator could still put out a voltage or sufficient battery voltage could pass back thru another component connection to the accessory post that would be enough to keep the coil energized so the engine would not stop.

Later cars with numerous accessories are prone to this issue but in 38 there may not be enough extra on the electrical system to matter. It will not hurt to try but if the engine keeps running then you will need to go back to finding a repair for the switch.

An option to prevent feedback is to use a high amperage rated diode on accessory wire to prevent feedback if you decided to share the accessory terminal the coil.

Look at the picture.

There is a common plate with a cutout to separate the coil when the key is off. When the key is turned clockwise the plate connects with battery feed. When the key is turned counter clockwise the only difference is there is no power feed.

The only reason for the separate coil feed is anti-theft. You can't back feed power to the coil without a short circuit.

On the subject of independent coil terminals, here is a breakdown of a later switch showing typical internal construction. As Tim said, most early cars will not have feedback issues because accessories are sparse and electrical paths are simple but later cars, particularly those with more than one power feed to an accessory or an idiot light charge indicator can. Some aftermarket accessories or one improperly connected can also cause issues.

I have not had any junk pre 55 ign switches to take apart so do not have any photos or a precise view of the internal contact action on those but since they have a BAT, COIL, and GA terminal I would wager, with a couple of exceptions, the internal contacts will work exactly the same way as the 54-6 switch. The exception would be that before 49 Packard had no left hand accessory position and before 54 there is no far right start position.

In this 55 switch the contacts are named using modern nomenclature. IGN would be the same as the earlier COIL and ACC is the same as the earlier GA. Obviously the contact plate would be shaped a bit differently on those pre 49 switches where there is no left hand position or on those 49-53 switches without a start terminal.

NOTE: While not applicable to the 38 model this thread is about, as an aside for those having key start cars look on the last (start) photo and see where the contact with the plate is made. Then check the other photos and look at the actual terminal contact point which appears on the photos as a black dot with a silverish color around it. That contact is formed by a raised "bump" pressed into the thin copper bar connecting to the center start terminal. It has a small contact point and on this switch the black dot is showing because it is a hole formed from the bump after metal was burned away exposing the hollow underside of the bump. The burning is due to the heavy current required by the pinion shift starter solenoid used on senior models. The burned away contact and a corresponding melted and warped spot on the plate is the usual reason the 54-6 switches fail. A reason why adding a relay to carry the heavy solenoid current is a good idea.

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I'm still working on the ignition switch problem. I think I have a solution that will work, but we'll see.

I had some time yesterday with the car, though I was unable to get the things done that I wanted to. I ordered a fuel pump rebuild kit from Then and Now 2-3 weeks ago but it hasn't come yet. I was going to clean and mount the air cleaner, but realized I'm missing the bracket that holds it to the exhaust manifold. The car has been disassembled so many times that the bracket could be anywhere.

I also realized I am missing the adapter plate for the hard vacuum line on the intake manifold. I'm searching for both of these parts, so if you have them let me know.

I needed to clear some space where the body panels were being stored, so I put the hood back on the car. I also loaded up the fenders and drove them back to my house 2 hours away.

I'm looking for ways to get the car to my house so I can put it back together in my shop. I'm only at my parent's house once a month, and I'm spending most of my time there helping my mom with various projects since my dad has passed. If I can get the car to my place I can work on it in the evenings and get it back on the road quicker.

-Kevin

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This is what the fitting looks like on our '37 Super-Eights. It was probably the same item on the '38s.

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I have made up the electronic controller for this security system where I live, so six volt electronic relays are an easy project.

Whatever feedback there is from the ignition system is present whenever the motor is running and can be mitigated using a capacitor at the distributor. The rest is absorbed by the battery. Trying to make up clamping diodes is not going to work because containing the primary voltage spike will affect the secondary and burn up the points.

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Thanks Bob. I need to find one of those adapter plates. Any idea where the other end of the line connects? I assume it goes to the vacuum pump, but does it go on the front or the back?

-Kevin

I think I may have the ignition switch figured out, I hope. I was unable to get the brass grommet/connector tapped as it would just spin around.

I ended up drilling away some of the bakelite so I could get a pair of hemostats to clamp and hold the brass grommet in place. Then I was able to use a #4 machine screw to self-tap and hold a connector in place. It holds fine, but the whole assembly spins because the grommet does. I can't think of a way to keep it from spinning.

So I cut out the back plate enough to allow for some movement without it contacting and shorting. For good measure I put some heat shrink on.

I guess we'll see how it does. I'm going back to where the car is on Monday and will get it installed. I need to get the car started so that we can load it up on a friend's trailer and get it back to my place. Then the finishing can start in earnest.

-Kevin

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Got up early this morning and worked on getting the ignition switch back in the car. As expected, it was a difficult task. Most of it was working blind, and getting the screws in by feel. Took a solid hour of laying upside down to get it done. I left it as a normal wire for now. I plan to clean out the armored cable and will run the wire through that. The armored cable will not go all the way to the ignition switch....it will be cut just inside the firewall.

The battery was totally dead, so after charging and trying a few times the car fired up and ran fine. It needs some tuning, but overall smooth and quiet. I took it for a quick drive around the street....clutch was okay but loose, brakes were not amazing. Both are on my list to address.

The temp gauge was showing over 200 in the car, the louvers didn't open at that point. Steam was coming out of the radiator cap. The mechanical fan is not installed, but I hooked up the existing electrical fan. I don't know that it did much. I'm not sure I can trust what the gauge says. The radiator cap may be bad also, letting pressure out. I will have a lot of diagnosing to do.

The louvers opened after I shut the car down, and closed slowly as the car cooled. I will read up in the manual on adjustments and see what I can do.

A friend of mine made the 2 hour drive down to the where the car was, and we loaded it into his enclosed trailer. He drove it back to my place and we just finished unloading it and putting it in the shop. With the car in the shop I will have plenty of room to work, and the lift will make it easy to get underneath and adjust things as needed.

For now, at least, my shop is fully dedicated to Packards and my Panama has a stable mate.

-Kevin

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