Multiple Voltage Reg. failures in 930
 

So here's the story...

In 2003 I had my alternator in the '82 930 rebuilt because of failing bearings, replaced the VR at that time. Ran fine for 1 year.

In 2004 the VR started failing and voltage would spike here and there... I replaced it.

Now, 2005 the car isn't charging again... Assuming another VR failure... Voltage was clean on a scope check previously. Battery in good shape and no funky electrics. Could there have been a bad batch?

I don't have a hard answer for you, only a rant.

I ran an extra alt ground foreward to the tub ground on Top of the strap to avoid such a crazy prob from happening. Some hard info is that technically an alt ground should be directly connected to the battery, not the engine case.

Chris, internal or external?

If you are not charging check to make sure the alternator light comes on when you first turn on the key.

The reason why this is important is that this circuit precharges the field coil. If the bulb or the diode in this circuit burns out a perfectly good 930 alternator will not charge.

I learned this the hard way after spending about $150 on having my alternator rebuilt and spending a couple hours taking it out and putting it in.

In the end an eighty cent diode from radio shack fixed the problem. That was after several hours of studying wiring diagrams and troubleshooting my electrical system of course.

I would think Chris went thru the routine circuit tests. It may not be a routine answer if I'm correct?