1939 Chrysler Solenoid/Wiring

[MercMontMars]

Hi there, I’m working on the electrical connections and wiring of my 39 Chrysler Windsor. I’m trying to get a little life out of the electrical system, but I wanted to ask some questions before I go pulling anything apart. 

Where I’m at right now is when I put a hot 6v battery in and hook the terminals I get nothing. It looks like my positive ground goes to the transmission and my negative goes to the solenoid. I’m replacing the cables tomorrow and cleaning my connections. 
 

Anyway, my question is, what are some things I should look for? There is some screwy wiring going on under the dash, someone’s obvious efforts at “restoring” the wiring. Looking at my solenoid, it looks original and I’m not really sure what is inside of these things.. can they really go “bad?” It’s all corroded but I’m wondering if it’s fixable or if I should try to find a new one. Will get some more pictures soon. My goal is to at least get some sign of life, dim headlights or maybe even a little spin from the starter.  The battery that was in the car actually took a charge, it looks relatively new which is odd to me. I don’t think someone would take the time to hook in a 6v battery on a non-functioning system but who knows.

 

Thanks for any help!

 

 

[keiser31]

You might look into purchasing a new wiring harness from Rhode Island Wiring or YnZs. They probably reproduce one for your Chrysler.

Edited September 18, 2023 by keiser31 (see edit history)

[MercMontMars]

@keiser31 Definitely gonna look into that, I want to try and revive what I have for now but once the car proves itself and runs I will absolutely buy a new harness, she’s gonna need it. 

[Bloo]

Something is miswired in your solenoid pics.

 

4 hours ago, MercMontMars said:

It looks like my positive ground goes to the transmission

That's good.

4 hours ago, MercMontMars said:

and my negative goes to the solenoid

Good. I cant tell from your solenoid pic which large post on the solenoid that is, right or left. Whichever large post goes to the battery should also have another wire attached. It is a big wire, but pretty small compared to a battery cable. It carries current from the battery to the rest of the car, except the starter, and carries charge current from the generator back to the battery. I see a ring terminal in the foreground. Is that it?

 

The small post and small wire is what triggers the solenoid and makes the engine crank. I don't know if you ground it or give it 6V to Make it crank. Probably you give it 6 volts. If so, it might start working when you get the main power wire hooked back up. What does this car have for a starter switch?

 

[Rusty_OToole]

Looks like a typical Ford starter relay. Power to the small post should make it click. If it clicks it should work, if not worn out or corroded to death inside. You might want to take off the wires one by one and clean and polish the ends of the wires with fine sandpaper and wire brush the posts. This fixes a lot of problems, corrosion builds up and causes excess resistance, 6 volt systems are patsies for this, more so than 12 volt systems. Just cleaning connections and replacing frayed and broken wires fixes a lot of problems.

[TerryB]

**** The shop manual supplement you are getting from me has the wiring diagram in it so you will have references.   I’ll send it to you as soon as I can.

[MercMontMars]

@Bloo I was trying to figure out that ring terminal last night, it looks like it goes to a relay that goes into the cabin. I’ll try hooking it up after cleaning my connections and see if it does anything. For the starter switch the car has a push button surprisingly. At first I thought it had a floor button because there’s two, but from videos I’ve seen on this car they start it with the dash button. Still don’t know what that other switch is for on the floor. Will get pictures of those today.

[c49er]

You have the overdrive 3 speed looks like too...you need that!

Make sure both front and rear cases are full.

 

[MercMontMars]

@c49er Indeed I do! I found the overdrive knob while tinkering with the interior the other day, thought it was pretty neat. Would you know how I might go about checking and or filling the transmission? I haven’t been able to look at it or access much since the car is on 4 flats. Will have that fixed soon.

[Joe Cocuzza]

Really stupid question.......but I will ask anyway.

Do you have a key for the ignition switch?

Even though the car has a push button for the starter the ignition switch has to be in the "on" position (using the key to turn it/probably to the right) in order to "distribute" power to the electrical systems. 

 

You can "jump" the solenoid terminals and that will spin the starter but if the ignition switch is not "on" the car will not start - no power to the coil, etc....

[MercMontMars]

@Joe Cocuzza I do not unfortunately, there was an ignition switch in the trunk however that has a key. I might try wiring that in soon, that way I’ll at least have a switch I can turn. My 52’ Pontiac has a push button switch, I always thought it was odd how you can turn the motor without keys, it won’t start but just the fact that you can is.. odd. 

[61polara]

This link will give you plenty of information on your Chrysler.

Directory Index: Chrysler_and_Imperial/1939_Chrysler/1939_Chrysler_Owners_Manual (oldcarbrochures.com)

 

[The 55er]

Your ignition switch is not original to the car. The original switch was called an "ignition lock switch and cable assembly" and looks like the top center item in the picture. It attaches directly to the ignition coil that's mounted through the firewall. 

[MercMontMars]

@The 55er Oh wow.. that’s good to know. I wonder how hard it’d be to find one of those along with an applicable coil. Looks like there is a special connection on the coil in the photo. 

[TerryB]

The shop manual supplement went in the mail today.  Help is on the way😀

[Oldtech]

I believe that un-connected wire with the ring terminal is the one that goes on the battery side of the solenoid to power the rest of the car. Touch it to the cable first and check for sparks in case there is a short someplace. 

[MercMontMars]

Some photos of today’s venture.. found out my new cables are FAR too short, gonna have to return those. Removed the solenoid completely so I can give it a bath and hopefully revive it to working condition. There was a mess off handmade wiring near the batter side of the solenoid, looks like a harness that goes into the car.

[MercMontMars]

This thing actually looks thoroughly rusted inside and out, I don’t know if it’ll ever be conductive again no matter what I do to it. Is there a way to open it up? I don’t really know how to work on these, if I even can.

 

https://intellaparts.com/p/CLA-6631939/solenoid_12_volt.html

 

Edited September 20, 2023 by MercMontMars (see edit history)

[Fordy]

It looks to me like the top is crimped over to hold it in place. Try gently uncrimping and pry it off - if it shot you have nothing to loose. Inside is just a coil of wire that moves a steel rod to close the contacts. You may be able to clean it all up and free anything that's stuck and reassemble it. I did that once with a GM unit that "is not a serviceable item" and its sill good many years later.

Steve

[TerryB]

That one button on the floor looks like a headlight dimmer switch.

[Oldtech]

7 hours ago, TerryB said:

That one button on the floor looks like a headlight dimmer switch.

I'm wondering what the second one is. Did someone have a starter switch bypassing the button start?  I think that I would get another solenoid. They should be available from Summit racing and the like. Maybe even NAPA

[MercMontMars]

@Oldtech I’m not sure, I haven’t looked too closely at it but it looks very out of place. I know for sure one is a dimmer switch but the other one I have no clue.. I’ll have to trace it and see where it goes and if it’s even factory. As for the solenoid I’m definitely getting a new one, just a worthy investment.. only trouble I’m having is that I found 12v ones that look like an exact fit for under $40 or one that’s labeled as a reproduction 6v solenoid for $80. Not sure if it’s interchangeable like that, I can’t imagine it’s a dramatic difference but I’m being very cautious because this is a well preserved 6v system and I don’t want to mismatch anything.

Edited September 21, 2023 by MercMontMars (see edit history)

[MercMontMars]

Gonna buy one of these and try it, it is identical to what I’ve got and it is for a 6v system. Guess we’ll see how it goes when it gets here. Excited to read up on my shop manual when it gets here, thanks again @TerryB! 
 

https://brillman.com/product/6-volt-solenoid-curved-bracket/?gad=1&gclid=CjwKCAjwsKqoBhBPEiwALrrqiNJqCqNXJemVoM03okuKE_pHMSJSJnmpGE-Cq21Arp_Vj5nCC56Z1RoCyO4QAvD_BwE

[MercMontMars]

So I figured while waiting for the solenoid to come I’d figure out what I’m working with, starting with the starter. I’m using a 6v battery with jumper cables, positive to positive ground and ground to starter to “simulate” a positive ground as the car would work on. I have my buddy stand on the clutch and I contact the negative cable to the starter cable. I get a little clunk then it gets stuck and I have to hand turn the motor to un-stick it. I opened the little inspection cover and all the copper inside looks pretty good, still shiny. What might be going on? I’m contemplating taking it out, but that’s a can of worms I’m not ready for at the moment cause then I have to realign it and all that fun stuff. 
 

[Bloo]

Take the spark plugs out and see what happens.

 

[MercMontMars]

@Bloo I tried that, no dice. Thought that would help too.

[MercMontMars]

I’m kind of wondering if my system just isn’t direct enough, the jumper cables are pretty long and I haven’t replaced my positive ground cable yet so it’s still sort of nasty. Guess we’ll find out once I put the new cables in and the solenoid.

[maok]

Pull the starter to test it on the bench, very easy and no worms to worry about 

[The 55er]

For the record, the Autolite starter #MCH-6101 that's on your car isn't the correct one for a 1939 Chrysler, its actual application is for 1949-1951 Dodges & Plymouths. According to my sources an Autolite #MAX-4020A would be correct for a 1939 Chrysler six. They're two different starters. That starter switch that you removed from the firewall to clean & replace isn't correct for a 1939 Chrysler either, that one that would be used with the MCH-6101, maybe someone installed that switch on the car so the incorrect starter could be used. The correct 1939 Chrysler switch looks like the one in this Ebay listing and it mounts right onto the starter motor itself. If I'm right this will be evident when you check out the wiring diagram in your shop manual when it arrives.

[MercMontMars]

@The 55er Hmm, I’ll have to check that out once the manual arrives. Pretty surprising if it’s not the right starter motor or solenoid, means someone must’ve had a later dodge/Chrysler and my 39 and just started swapping parts back and forth. Hopefully nothing was messed up too badly by them doing this.

[MercMontMars]

Took the voltage regulator and a relay off for cleaning and inspection. Everything looks pretty alright to me, I’m no professional but good for 80 years old if they’re original. According to my research the relay is for the electric overdrive, not sure if that’s correct. Hopefully the shop manual will be here soon so I can check out the wiring diagrams and see what’s what. Found a weird plate that was on the firewall, took it off to see if it said anything or was blocking a hole in the firewall but it’s just kind of there. Distributor looks pretty clean.

 

 

 

Edited September 23, 2023 by MercMontMars (see edit history)

[Joe Cocuzza]

The plate.....

[MercMontMars]

@Joe Cocuzza Wow, I gotta find a reproduction of that. Mine is only a piece of metal after so many years!

[Joe Cocuzza]

https://www.ebay.com/itm/204086662290?var=0&mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338590836&toolid=10044&customid=f2218d2af8ba15e05880e8249e094479

[MercMontMars]

So now I’ve got a brand new 6v solenoid installed, and I wired it all up just as it was when I found the car. I also installed an ignition cylinder that I have the key to, wired it as it was to some nondescript black wires.. no idea where they go as of now.  The underside of the dash is very.. tinkered with. I got the lights to come on which is exciting, and I found my amp meter gauge to be working. Only thing I can’t get to go is the starter button. I’m not sure if it’s just too corroded to actually do anything or if something is wired wrong somewhere. Amp meter doesn’t move at all when the button is pressed so I’m assuming there is no circuit being created by it. I have a wiring diagram, but someone changed the setup to a different solenoid and later starter which confuses things a little bit. I’m sure I’ll work it out with some tinkering, but if I can’t figure it out as is, is there a way to safely bypass the ignition system so I can run the motor? Sounds like a dumb question, but I haven’t really dealt with a situation like this before and I don’t want to burn anything up so I’m just playing it safe. I’m still suspicious of the second floor button, it’s very odd. I plan on getting a fresh wiring harness for this car eventually cause it’s gonna need it, but I want it to prove itself first by running and moving. 

 

[Bloo]

Make sure it is out of gear, touch hot with a jumper from the post where the battery cable connects to that little post in the center. That should make it crank. If that doesn't make it crank, try grounding the little post and see if it cranks.

 

Once you know whether it wants hot or ground to crank (probably hot), check and see how your starter button is wired and which it does.

 

[MercMontMars]

Worked a bit more on the car’s wiring today, tried to get my ignition system to show some life but had little luck. I peeled away some old electrical tape someone used to protect the wires, but it looks like it might’ve just trapped moisture over time and now I’m left with a crumbly corroded mess. I was able to trace my wires a little bit and figure out where they go, but most of them have lost their colouring. Not really enough left of the original wiring harness that I can fix just enough to work. I am able to jump the solenoid directly like Bloo said, and luckily my starter turns strongly with all plugs in and torqued. My plan now is to find a safe way to directly run the coil for spark and be able to turn the motor. Once the motor runs and I get gears I’ll install new wiring but it needs to prove it’s worth first. 
 

Edited October 1, 2023 by MercMontMars (see edit history)

[Ben Bruce aka First Born]

Temporary?

  Perhaps a toggle switch with power running from battery, through the switch, to the coil. An intermittent toggle switch with power from battery through switch to starter post Bloo mentioned . Just unhook original wires at their termination ends and tape. Switches wouldn't even need to be mounted.

 

  Ben

[Bloo]

What Ben said^^. On most 6V cars, and that includes all of them that have a "normal" looking ignition coil, all you need to make the engine run is a switch to provide power to one small coil terminal. On a positive ground car, the power goes to the small (-) terminal, and the small (+) terminal goes to the distributor.

 

If you wire it up for real, supply power to the switch from the generator side of the ammeter. Use the "BAT" terminal on the regulator, or whatever the other end of that "BAT" wire connects to under the dash. Considering the condition of the wiring harness, I think I would run the wire right from the battery temporarily for a test, just like Ben suggested.