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Old 09-07-2012, 09:33 PM
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I've burned up two alternators in a month

Have a SBC with EZ harness, GM alternator, pretty plain vanilla setup. We ran the car for a couple months and the battery started running down. Checked the alternator and the white wire connector on the alternator was melted. I put on a new plug and moved the red exciter wire from the hot lead on the alternator to the unused electric choke wire on the EZ harness (keyed 12V). Thought the lead might be over voltage being hooked directly to the alternator out. Had another chrome alternator in the shop so installed that one at the same time. That ran for less than a week and it fried too. It melted the white wire this time but just 3" back to the blue wire splice I used to install it. The rest of thst wire was fine. I took the splice apart and the end farthest from the alternator was blue on the very tip but clean copper the rest of the way. Almost looks like a bad crimp? I got a repair kit and rebuilt the first one and found the internal regulator fried and one diode out, the windings were fine, no sign of other problems.

Anyone have any ideas why I am burning the idiot light lead and internal regulator?

My thoughts;

1) bad crimp on the white wire connector causing high impedence in that circuit? Doesn't make sense 'cause the circuit is designed to have resisitance in it (light bulb).

2) run down battery requiring the alternator to recharge it and in our 100F summer weather overheating the regulator?

3) other?

Thanx in advance for the help!
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