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I have a 68 442 4 speed. Wiring is a bit of a mess. Long story short, the purple wire for the neutral safety switch coming of the starter is heating up when the key is in the on position. I just found this. I also found that the black with yellow stripe wire that is supposed to go from the coil to the ignition was cut, and instead there is a solid black wire that follows the coil yellow down to the starter. Haven't found the other end of the black wire yet.
Seems to me someone did a crazy method of bypassing the resistance wire. It has points on it and I'm chasing an ignition issue and now think all of this is related.
Any suggestions on how to remedy this until I can afford a new harness? I'm thinking of starting with removing the black wire and reconnecting the black/yellow wire using a similar gauge. Then I'll see if the purple is still getting hot. If it is, I'll disconnect and cap it off since I don't have a neutral switch.
Thanks in advance all!
Adding a picture.
Last edited by Nick I; Jul 5, 2024 at 07:11 PM.
Reason: Adding photo
The purple wire is the power feed for the starter solenoid and should only have power to it when the ignition key is in the start position, so you need it. The yellow wire is connected to the purple wire at the starter and provides 12 volts to the coil only while starting. The resister wire then provides reduced voltage (6~9 volts) to the coil for normal operation so the points contacts will last longer. Whoever added the black wire wasn't able to understand that or just couldn't make it work like that.
It sounds like power is feeding through the coil wire into the starter solenoid wire but it is not enough to engage the solenoid. If your '66 has the same plug near the horn relay as the '67 in the photo below, try unplugging it once the engine is running and check both sides for power. There shouldn't be any! Those wires should only have power with the key in the start position. If they have power, try disconnecting the "black wire" that has been added.
The purple and yellow wires should be connected together at the solenoid terminal. The yellow wire and the resister wires should be connected together at the coil (+) terminal.
The purple wire is the power feed for the starter solenoid and should only have power to it when the ignition key is in the start position, so you need it. The yellow wire is connected to the purple wire at the starter and provides 12 volts to the coil only while starting. The resister wire then provides reduced voltage (6~9 volts) to the coil for normal operation so the points contacts will last longer. Whoever added the black wire wasn't able to understand that or just couldn't make it work like that.
It sounds like power is feeding through the coil wire into the starter solenoid wire but it is not enough to engage the solenoid. If your '66 has the same plug near the horn relay as the '67 in the photo below, try unplugging it once the engine is running and check both sides for power. There shouldn't be any! Those wires should only have power with the key in the start position. If they have power, try disconnecting the "black wire" that has been added.
The purple and yellow wires should be connected together at the solenoid terminal. The yellow wire and the resister wires should be connected together at the coil (+) terminal.
I'm working on a 68. I dont have that plug. Wiring diagram shows the purple wire going to a neutral safety swith then to the key cylinder. Since I have a 4 speed, there's no switch so assuming it runs from the starter, to the bulkhead and from the bulkhead to the key.
But I do agree that the black wire on the coil is connecting to somewhere it shouldn't and probably invopving the purple wire causing the heat. I'll chase it tomorrow and see if resetting it to stock fixes the hot wire.
The yellow and the purple wire are not connected together, the yellow goes to the R terminal of the solenoid and the Purple goes to the S. With a 4 speed the plug that would normally go to the NSS is jumpered.
D'oh! I really did read that but for some reason 66 stuck in my brain.
No worries! I've about got it all sorted but not sure about the starter wiring. The diagrams aren't clear, or I'm too thick, and I don't trust how it was wired. Does this look right or should the purple and yellow be swapped?
