ltboltman

Thanks for your thoughts and experience on this; I have not checked batteries with voltmeter- everything had been normal until I started it up the other day and the GEN light goes on - I've had a mental block on trying to resolve this simply, and not dump it off at the dealer; I was putting alot of weight that the alternator was OK because autozone said it was, but as you indicated, this may not be so. I've got a fishing tournament next weekend, so I'm running out of time to deal with it...prob just take it to dealer...I will post what the results are. Thanks again for all the good info.

Haulin_in_Dixie

The elementary test for a bad alternator/regulator. Pull the field wires off the alternator, the two small wires. Hook on terminal to ground the other to the battery. It will either charge full out or not. If it charges it is the regulator, in this case the pcm. If it does not charge the alternator is bad.

ltboltman

Thanks for the test info....think I could do that one...anyway
I dropped truck off at dealer at 10am - they called at 4pm and said the alternator diodes were "spiking"....