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> Charging light anomaly **UPDATE**
whiterabbit
post Mar 30 2021, 12:59 PM
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I've been browsing this site for awhile, as I restore my '75 914. I'm mostly done, just working on finishing touches and some drivability issues. You guys have been a huge help but the details of my current issue has me stumped. Below is a summary of the issue:

1-With key OUT of the ignition the charging light is "ON" (IMG:style_emoticons/default/WTF.gif)
2- Key in on position, the charging light turns "OFF", oil light turns "ON"
3- Engine Running, charging light is "OFF"
4- Engine running, voltage regulator plugged in, voltage at battery reads 12.4 volts (not charging).
5- Engine running, voltage regulator unplugged & jumper between D+/DF voltage at battery reads 12.6-12.8 volts (still not really charging).
6-Occasionally, ignition key needs to be cycled several times before the starter is triggered to start the car (probably unrelated?)
7-Charging light turns "OFF" when alternator plug (specifically DF connection) is disconnected from relay board.

Background info: New alternator 100 miles ago, belt tight, newer voltage regulator, new alternator wiring harness, newer ignition switch, transmission to trunk floor ground strap clean and tight. 20 miles ago, the charging system was working as it should.

My theory: Alternator failure! But I don't want to throw parts at the situation if there are other clues in points 1-7 above.
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GregAmy
post Mar 31 2021, 07:06 AM
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Remember, the light comes on by a differential in voltage...regardless of the direction.

I thought it strange too, but it's certainly possible that an internally-shorted alternator could provide the hot side, and something in the keyed hot circuit could find a ground somewhere.

I'd start by disconnecting the three-prong plug from the relay plate and seeing if the GEN light stays off. If so, then you have a clue that that end is suspect.

Pulling the alternator is such a god-forsaken PITA hassle that once out, just get the damned thing rebuilt so you don't have to do it again, even if it checks good.
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