Good evening folks, and Merry Christmas. My truck has been described as a “wiring nightmare.” It’s true but I think Im getting somewhere. Maybe someone on here can help me out. My latest issue has is when I start the truck it will only stay running in the start position with the starter engaged. When I let off the key truck shuts off. I have removed my ignition switch and hot wired the car but had the same problem. So it wasn’t the ignition switch and it’s not the ballast resistor. I did however manage to keep get the truck running by adding a hot line from my battery to the positive on my coil. I even put an additional ballast resistor in that line. So the truck runs but it runs like ****. In fact it barely moves when in gear. If I run that extra hot line directly to my coil without a ballast resistor the truck runs seemingly normal. I didn’t drive far like this because I know thats bad for the coil. my starter relay and starter are brand new along with the coil and distributor. I don’t know where to look for my problem besides figuring out how to do a full rewire. Any help whatsoever would be greatly appreciated.

 

Is there another ballast resistor in there somewhere? Have you tested resistance across the coil? (it may not actually need the ballast resistor.....)

Have wiring diagrams for your truck? If not, that's where you should start. Find a factory service manual for your truck. Should be able to download one for fairly cheap, if not free.....

 

Have you replaced the ballast resistor on the firewall yet? Long time Mopar owners back in the 60's and 70's would carry an extra wrapped up in a towel in their tool box. When they went bad, it may run, or it may not. If it's good, then you have a problem in your primary ignition circuit. Did you splice into the wire or replace it with a hot wire? If you replaced the primary with a hot wire, you may have a dead short. The start position bypasses most of the power, including the ballast resistor. The run position goes through the resistor.

I'd replace the resistor first. Next, I'd look at the brain box. All the street engines used the same one if I remember correctly.

 

the ballast resistor on my firewall is new. I had this thing at a shop and just got it back in working order but then problems returned. i didn’t undo any wire to the coil. i simply added one to the positive. this added wire makes my truck run and drive ‘normal’ but when i put a ballast resistor in that added line the truck sounds bad and barely moves. If my truck has a brain box or some early veracity of one it was replaced at the shop. probably one of the shiny new pieces on my first wall with a ton of wires around it. i’ll look into testing resistance on my coil.

 

Coils fail very rarely, but go ahead and check it. I think in the last 60 years I've replaced one coil because it failed. I've put hotter ones in and my pickup had rodent damage to it when I got it, but they are one thing that doesn't fail very often. Your brain box is your engine controller. New ones are usually orange but I've seen them silver too. It has a simple plug on it held in with a single screw. I would pull it off and clean the ground where it meets the body. It grounds through the body.so make sure the body is clean with no rust where it bolts down.

If that doesn't help, you have a wiring issue in the primary circuit. Look around for wires that look like they aren't connected or have insulation or other damage.

 

You have two wires coming from the ignition switch, One is hot when cranking and the other is hot when in the run position. Chrysler i believe had three different resistors but the print below shows you how it works.



Another thing to check is the wiring running threw the firewall. The bulkhead connector the terminals heat up and melt it. This may be the issue with yours, And if you didn't already have a look at the wiring going to the amp gauge. The terminals on the back heat up and in the bulkhead connector. You don't have to swap to a volt gauge but it will eliminate all the amperage running up to the gauge. Link below will show you...
http://www.madelectrical.com/electri...p-gauges.shtml

 

yeah the coil and distributor are both brand new. thank you for your time and the diagrams. I think it’s probably a wiring issue. gotta trace em all down. i’ll get back into next week. Merry Christmas!

 

See if you have power at the coil with the ignition on. If not, there's yer problem.

 

the ignition wire that was used for my coil failed somewhere behind the dashboard. (wiring nightmare). so that was the problem. a new hot wire is being used and things are functioning as they should and we’re up and running! thanks fellas