How do you tell when an '82 alternator is on its way out?

[saurkraut]

Is was driving my '82 930 the other night, and I thought that the lights got bright a couple times. I checked the belt, and it was a tad loose. So I tigntened it. A breif drive with EVERYTHING on and I saw no power fluctuations.

I just read in a Motorbooks Porsche buyers guide that this car has a 1,050 watt alternator. Appearently, some of these alternators like to overcharge the battery and burn out other stuff.

How do you check if its overcharging?

Thanks

Karl

[rnln]

start the car, let it idle, measure the voltage. Usually it's around 14+ volts. If it's 15v or more, it's over charging. I don't remember the exact number but around there.

[carreraken]

Had similar symptoms when mine went out. Used a voltmeter to monitor the voltage and it would occasionally spike to 15v. Had the alternator replaced.

You can also get a cheap voltage monitor that plugs into the cigarette lighter - that's what I use now.

[saurkraut]

13.9 volts.

Geuss it was the loose belt.

Thanks!