wiring question

[stuntmanmike]

So a few weeks ago had a small electrical fire. Source I believe was the alternator or lack of the wiring being able to handle. Either way the red wire from the alternator all the way to the ignition switch melted. Currently, I have installed a new alternator and new ignition switch. In the picture, you can see that half of the original is gone.

In picture 1 what does the black wire do on the connector? anything

right now it cranks and starts but as soon as I let go of the key it stalls.
the wires are connect as seen on the plug

suggestions?61434973258__7AE97A83-8847-4692-8045-1B8D053FD9A4.JPG

61434974398__86AAEB34-7D21-427A-9C64-70D3B1E4F234.JPG

[712edf]

When you are cranking the coil is getting 12 full volts from the battery via the ignition switch (I think connected to starter relay). When you release the key from "start" is goes to the "run" position. This routes the power to the coil through the ballast resistor & reduces voltage to about 6 volts. Sounds like your ballast resistor is bad, or more likely the wiring to/from it is destroyed.
I will have to look at my books & get back with you on the actual purpose of that black wire.

Bucky

[stuntmanmike]

Bucky, you were right, I replaced it and the connector to it and it starts and runs fine now.

So my next battle is now every time I turn right the horn blows. which led to searching the rest of the wiring and finding now directionals or hazards. That will be this weekends project
thanks for the reply

[712edf]

Many of Dodge's electrical circuits work with continuous voltage & are switched "On & Off" via the ground leg of the circuit. I believe the horn is this way. When you press the horn button, the "switch" closes, completes the ground circuit & the horn (which already has positive voltage) will blow. The gauges work with a sender on the ground side of the equation.

What you are experiencing, fire or not, is normal. All 70's Dodges need to have virtually all the wiring removed & reworked. It was hokey when new & previous owners have always done stupid modifications.

Bucky

[stuntmanmike]

Thanks for the input, it has kind of been like pulling a string on a sweater.

[712edf]

Yes,

Keep asking questions. I got books & plenty of firsthand experience on these 70's trucks. I don't know squat about the military or the Flat fender PW's.

Bucky