Anyone know what would cause my amp guage to suddenly fluctuate wildly for about 5 minutes then return to normal. I have a 100 amp alt with internal regulator (new) and the car has all new wiring harness (last year)...everything has been working perfectly...and today while out driving around my amp guage just went crazy in every direction... Any ideas appreciated!

Thanks,

J

check for loose connections including grounds and at the alternator.

What kind of vehicle?