Replaced Alternator, now won't charge
09 3.6L, 150K. Heard that that the ECM/PCM has to be reprogrammed to get the alternator back online. "Service charging system" is still there as well at battery light. Battery 1 year old, tested good under load, no output from alternator. I'm a Certified Electronics Technicion, Aircraft Electronics Technician and mechanic and have bee to 5 car manufactor's drivability schools, not bragging I promise, just a background. The initial scan showed a U1000, not good but can be triggered by a alternator weird failure. Put new serpentine belt on also. Car starts fine and all electronics work fine, but no matter the rpm, no output from alternator. Very little experience on Buicks and 1st car I've heard will turn off the alternator once failed in the ECM and have to be programmed. True or not true. I do this for friends who are paycheck to paycheck and if I made it through working on MGB's Fiat's and Saab and Alfa Romeo's, I can do this with a little help from my friends. 1st and most important issue is to find out if after ALT replacement only a dealer can reprogram? After ALT replacement even with no out put ran the car a lot, then recharge the battery and the U1000 code never came back, not even pending. Thanks to all for your ideas and help.