Truck--91.5 d250 ---PCM regulates voltage by switching grd. rapidly. Is this the reasonmy amp gauge(and test light ,on gren wire on the back of alt., ) "BLINKS"??? Would a internal reg fix this problem????.



whosdunit.

 

A 91.5 model has a external regulator. It should be mounted some where on the firewall around #6 valve cover.

 

Yes .sir it does ,my problem is --it is pulsing at idle, and my amp gage flips back & forthand since the pcm don't need the alt., input --wouldn't a internal regulator fix my problem.?

whosdunit.

 

yes, some put the 150 amp ir gm alternator, as another alternative look at jims post with leece nevill, I like the easily accessable brushes and regulator, mine pulses at startup, usually from camper battery being down, after a minute of running its normal.

 

Thanks guys ,,headed to alt. shop this morning to see what it will cost,,and get grd., cables via the sticky.


whosdunit.