Voltage regulator question
 

Last week, I had part of my wiring harness catch fire. The PO had a 20 amp fuse in the 15 amp engine socket, which is the only thing I can think that might have started it. It also didn't help that he had removed the fusible link wire. The weird thing is I have driven the truck a few times up to 80 miles and nothing ever happened and when the fire started I was just letting it warm up in the driveway. I cut out the bad part of the harness and soldered in new wires to fill the gap, but now I seem to have a problem.

The truck starts and I know I have all the wires in the correct places, but the truck won't stop running when I turn the key off, I have to pull the hot wire to the coil to shut it off. I have not taken it out of the driveway with it is this condition. I think I know what the problem is, but I just wanted to get a second opinion.

There is continuity between the brown lead to the coil and the red wire that goes to the external IC voltage regulator, which there should not be. There should be power to the coil lead only when the ignition is on, but I can start the engine without the engine fuse. The truck starts and turns off just fine when I unplug the voltage regulator. Is it possible that during the fire I fried something in the regulator and that is allowing power to get to the coil lead? That is kind of what it seems to me, but I would just like any other thoughts on this before I get a new regulator.

So, should I get a new regulator, or continue to chase wires?

Thanks

Zack

I looked at my wiring diagram: Brown wire goes to the ignition switch (B-Y wire) There is a Condener (Blue (L) wire) in the Ignition circuit near the igniter-check or replace it. There is a Condenser (Blue (L) wire) in the voltage regulator circuit-check or replace it. If replacing the condensers does not solve the problem then it is most likely that you have a short / problem in your ignition switch. I say this because you never mentioned that you had a battery charging problem or that the charge indicator stays on. The Engine fuse also supplies power to emission components: Fuel Cut Solenoid, Cold Mixture Heater Relay, Etc. and the Cold Mixture Heater Relay Contact supply power comes from the same circuit of the ignition switch-Black / Yellow wire.