intermittent excessively high voltage from alt - 08/08/06 11:03 PM
My alternator has been putting out an excessive amount of voltage intermittently the last couple of days. I just installed a 200 or 250 amp (I can't remember which) alternator from excessive amperage 2 weeks ago. The 3 wire harness was the typical ford alt harness and did not fit with my stock wiring, so I bought a new connector and wired it in. I don't believe this is part of the problem, but 2 of the wire colors were different, so I just matched up the wires location with respect to the factory wire harness.
My alternator seemed to work good for a couple weeks, but recently it started giving way too much voltage. My stereo measured 15+ volts (only measures up to 15v max) but it seems like it was more than that. It was enough to blow my head lights and a small 12v inverter. It also caused my gauges to stop working/go crazy during the over voltage situation. The problem seems to only happen at low rpm around town driving. If I keep the rpm's above 3,000 it never happens.
I was convinced it was a short somewhere. I thought that one of the sensing wires off of the 3-wire connector had been rubbing up against some metal somewhere. I took off the wheel last night and played around with some of the alt wires. I couldn't see anything wrong, but I couldn't see in there very well either. After moving those wires around last night and driving today, the over voltage problem hasn't happened sice (yet).
I have already performed the Ford TSB for the "flickering lights" problem. (relocating the voltage sense wire directly to the positive output terminal of the alternator)
Does anyone have any ideas about what I should check?
My car has been driving bad too (revving to 3,000 rpm in neutral while slowing down), but I imagine that is probably related to the voltage problem as it seems not to happen anymore when the alternator problem subsides for a while.
Thanks for the help
My alternator seemed to work good for a couple weeks, but recently it started giving way too much voltage. My stereo measured 15+ volts (only measures up to 15v max) but it seems like it was more than that. It was enough to blow my head lights and a small 12v inverter. It also caused my gauges to stop working/go crazy during the over voltage situation. The problem seems to only happen at low rpm around town driving. If I keep the rpm's above 3,000 it never happens.
I was convinced it was a short somewhere. I thought that one of the sensing wires off of the 3-wire connector had been rubbing up against some metal somewhere. I took off the wheel last night and played around with some of the alt wires. I couldn't see anything wrong, but I couldn't see in there very well either. After moving those wires around last night and driving today, the over voltage problem hasn't happened sice (yet).
I have already performed the Ford TSB for the "flickering lights" problem. (relocating the voltage sense wire directly to the positive output terminal of the alternator)
Does anyone have any ideas about what I should check?
My car has been driving bad too (revving to 3,000 rpm in neutral while slowing down), but I imagine that is probably related to the voltage problem as it seems not to happen anymore when the alternator problem subsides for a while.
Thanks for the help