What just happened?

[Tincture77]

After installing a rebuilt alternator on my 73 t'all 1110 392 2wd, I took it out on a test drive to log data for my recently installed afi fuel injection. The battery was reading 14 volts at idle from my voltmeter, so the alternator was working. After about 10 minutes into the test drive upon hard acceleration, the starter engauged and would not turn off (even with the key out of the ignition switch). One of the wires going to the negative terminal on the ignition coil was red hot. After frantically searching for something to disconnect the battery, we got it disconnected and let her cool down. What happened? Could I have connected the two wires that go on the slot connectors on the bottom of the alternator incorrectly causing this?

 

[Tincture77]

Ok, upon further investigation one of the wires I mentioned shorted out to the hot manifold. The position of these posts was a little different than on the previous alternator. After unshorting this wire and connecting the battery back up , the car starts but wont turn off even with the key out. Even after disconnecting the positive battery terminal it still ran. I had to disconnect the ignition coil wire to get it to stop.

 

[towpainter3]

Without any more info it sounds like your ignition switch on the column has shorted to run all the time or your power wire to the coil is shorted, probably melted through to another hot wire in the harness and continuing to draw power. Start tracing wires looking for melt through and check the column switch.

 

[Tincture77]

The section of the wiring harness that goes to the alternator/ignition coil and the other end that goes to the starter was crispy. I was able to repair and rewrap most of the wires, but a couple were completely fried and uninsulated. I tried hooking up all the wires as best as I remembered but no go. The black and white super small text wiring diagram that I have is less than helpful. Where does the wire that connects to one of the 2 post connectors go to(not the one that goes to the dash amp meter). Also there was a mystery small gauge brown wire with a white stripe in this harness section that I can't identify.