Last time I had a 944 voltmeter pegged at the 12 volt line exactly, my alternator failed shortly thereafter. Is there any way to test the voltage regulator? Normally it's closer to 13 volts, today noticeably decreased to 11.9-12.1, ever-so-slight increase with rpm.

Re: 1992 968

Thanks.

 

With the car running, disconnect the field wire from the alternator (white molexish connector near brake booster, red-black stripe and blue wires.. field wire is the blue one)

The volt meter should start bouncing wildly over 14V

If it DOESN'T do this, you either have poor wiring or a bad regulator..

If the regulator is bad, might I suggest the Nissan quest alternator swap? I have done 2 of them now, they are really quite easy, cost 1/4 of what the replacement Bosch alternator costs.. output is higher, and rather than the old Bosch style, it uses an almost bullet proof nipon denso regulator..

 

Mine is always 12 twelve except right after startup when the battery is 'thirsty.' I'm not too worried about it because the battery is always strong, even after leaving the fog lights on once or twice

 

I would clean all the grounds. I have noticed my battery started to charge more after I did this. Makes sense some of them were really corroded. Do that first then recheck. Or put a voltmeter on your battery while the engine is running to see if its charging.