Hi

I have a 1982 928S 4664cc manual Euro with CIS injection, recently all the warning lights came on and we discovered the Alternator had failed, the regulator and recifier was changed and on a bench it give 14 volts, when fitted on my car the volt meter reads 12v, never goes higher, it stops there as if there is a stop on the guage, when I trun the lights on it drop to 11.5, with main beam and fog lights 11volts.
Is there another regulator on the ccar to control the voltage somewhere.

i also noticed that I have lost all the lgihts that illuminate the instrument pod although i dont think its related

Adive needed

BTW the battery doesnt go flat!

Thanks
Paul

 

Check the voltage with another meter. You might be surprised.

My dash lights are finicky as the rheostat is dirty. Work it a bit. It's on the left underside of the pod with the trip odometer reset. Otherwise check grounds and fuses.

 

Check with a VOM at the output terminal on the alternator.

 

There is an adjustment pot on the gauge that can bring the reading to a better level. You must pull the pod to get to it. That would be a good time to clean all the contacts, rheostat, and replace bulbs.

 

Also, do the Wally-groundpoint clean-up.

After cleaning the ground points and the battery terminals, my dash volt meter read 12v and went down to less that 11v with the lights on. That was a bit nervous at night, alone on the prairies!! A digital VOM showed me that I really had 14.2v and 13.8v respectively......... quite healthy, indeed. A quick twist of the trimmer pot beside the gage while I was replacing bulbs for the idiot lights, and it's all good, again!!

 

Just to echo what has been said before, check the voltage at the jump points with a voltmeter. It is probably fine. Then when you do pull the pod (because I bet it is related) to clean the contacts spend the extra 50$ (plus $150 in shipping to Malta :-) to replace the circuit board. When I did that I gained about a volt and a half on my average volt gauge reading. While you are in there replace all the bulbs. IOr you are really ambitious toss the dash illumination bulbs and put in LEDs (they rock! Search for LEDs and you'll find links to the procedure. It took me about 3-4 hours to do the whole thing).

Also by changing the circuit board you won't be posting about your speedometer and odometer problems in 6 months. :-)