Resistor wire and choke wire hot

[67GMC]

So, I removed my AC unit as it wasn't working to clean up under the hood and under the dash. Put the alternator back with "w/o AC" belts and everything ran fine. I went to turn my parking lights on and the fuse went. Odd. I replaced the 20A fuse, again, instantly blew.

I pulled all the lights off (head lamps and running lights and fog lights). Still blows the fuse. I disconnected the firewall connector to the front wires. Still blows parking light fuse! Disconnected harness to rear lights. Still blows fuse. Getting mad now.

I took the split loom off and examined wires. Lots of duct tape!!. Removed that, still blows. Did grounds all over, nice and shiny... No change. I changed the headlamp switch. No change. Blows fuse instantly.

I had my cassette deck playing a Boxcar Willie tape while I was working today. I put a 20A fuse in but didn't pull the parking light switch out. Everything works inside (courtesy lights, tailgate up/down, mirrors, seats, horn etc, blower motor etc. I went under the hood to re-do the coil wire clip (why not, I've got it apart). The electric choke was almost too hot to touch and the exciter wire/resistor wire from the alternator was also really hot. I traced it back to the bulkhead connector and it was hot all the way there too.

Do you think this is the ammeter going bad or do I still have a short circuit somewhere. Very frustrated at this point.

[tgreese]

Duct tape was used by the factory to insulate the splices. Not an issue.

Leaving the key on without the engine running is not a good idea. This is why the "accessory" position is available on the switch. The alternator exciter only has current when the engine first starts, to excite the alternator. No current flows once the alternator is charging. Not surprising it gets warm when sinking a constant current.

[67GMC]

Thanks for the reply-Do you think the excitor wire/resistor wire would be hot to the touch? It looked pretty shriveled by the time it got to the bulkhead harness. I noticed that the ammeter while running was indicating a lot of current on the charge side. I took this to mean I had the battery run down and it needed to charge more than normal. Still moving wires around at this point.

[tgreese]

I don't know what the alternator should sink normally. Once started, the alternator self-generates, using its generated current to power the field and make more current. Since the field connection is then at the same voltage as the ignition, no current flows. Possible you could have a bad diode in the rectifier that's sinking a lot of current through the field connection. Or something else wrong with the regulator. Just speculating. Or maybe sinking current with the key on is normal.

JMO - keeping the ammeter in the dash is risky. All the charging current goes through the bulkhead connector, through a screw terminal on the ammeter, through the shunt in the ammeter, out another screw connector on the ammeter, and back through a second bulkhead connector to the solenoid and then the battery. Lots of opportunities for connector failure there...

[67GMC]

Thanks again. I've got all the wire harnesses apart now. Just repairing some of the burned wires. I ordered some new turn signal sockets as mine were very sketchy. Jeep's are bad for wiring for some reason. Many crimps in the wire bundles.
I've read a few posts about replacing the ammeter. I want to get it back working (lights and all) first so that I know the basic wiring is ok. I've removed cruise control harness, all A/C harnesses and piping, washer pump, headlamps, fog lamps, etc. Trying to get back to basic operation. Finding issues or soon-to-be-issues along the way as well.

[67GMC]

Just an update. Pulled apart the harness the goes to the alternator and solenoid. Another mess of crimps, nicked wires and old electrical tape. Cut and remade connections. Parking lights now working!! Now I just have to put everything back together. It looks like a rats nest of loose wires but at least no apparent shorts and a lot better ground connections. Also, just a note that the headlamp switch grounds to the dash. I wish it has it's own ground wire.