steva

I recently installed a replacement engine wiring harness on my 64. Once started, the key would not turn off the engine and the coil got real hot. Any ideas?

Avispa

Sounds like your starter solenoid is faulty, so that the "I" terminal remains hot even after you release the key from the START position. That would account for both the engine not shutting off with the key (+12V goes straight to the coil from the pink wire on the solenoid) and the coil getting hot (the same pink wire bypasses the ballast resistor during engine start to make more voltage available at the coil).

Once in a while a bad voltage regulator will allow enough current to remain in the harness after key shut off to keep the engine running, too.

steva

Thanks! I replaced the voltage regulator with new solid state technology, I"ll replace the solinoid.

raylag64

Did it run fine before the new harness was installed? If that's the case, then you probably landed the wires wrong on the solenoid. I would double check it before changing parts out.

Avispa

Ray, you could be right, but think about this, if the pink wire from the ballast resistor is connected to the S terminal on the solenoid, just turning the key to the ON position would crank the starter. The starter would continue to run as long as the key was in the ON position, even after the engine started. Turning the key to OFF would kill both the engine and the starter because the purple wire improperly connected to the I terminal on the solenoid isn't connected to anything else in the electrical system unless the key is in the START position.

Not sure the OP described the problem this way, but that's how it would work.

DUB

Your problem can be as simple as the outer terminal on the solenoid where the wire that goes to the coil is touching your 12 volt battery terminal on the solenoid. I have repaired many "do-it-yourselfers" cars due to this issue...due to this terminal rotates and can touch the battery cable on the solenoid and keep the coil energized.

DUB