The alternator is only putting out 20 amps.

First of all, I'm not clear on whether this alternator has the integrated voltage regulator, or it's separate.

Second, even if it is separate, how can I tell whether it's the VR or the alternator that's toast ?



* '95 964; '94 854; '80 242GT
* gone but not forgotten - '89 744; '80 242GT (Bertone Red !)

I have found charging problems on the 850 to be more likely the pos. battery cable.Check for voltage drop at battery end of cable or fell for heat where cable is crimped to end,after running awhile.If warm or hot replace cable or end at least.Also check ground cable connection @ battery tray.

The alternator has a built in voltage regulator.
You can get the regulator by itself but it costs as much as a rebuilt alternator.
What are your voltages? idle? 2000 rpm?

You can get a knock-off turd bucket rebuilt alternator for the price of a new Bosch regulator/brush holder assembly but a rebuilt Bosch alternator will set you back twice as much as the regulator. You pay your money and you take you chances. Myself, I install only Bosch alternators in my shop and even at that I still have had a Bosch fail prematurely but it is very, very rare.

Mark