On my 2008 Chevy suburban while driving for approximately one hour my
voltmeter will drop to 13 V occasionally it will come back up to over 14 and
then drop back down to near 13 I stopped checked with voltmeter and it was
charging at 12.9 to 13 V I replace the alternator and about one hour after
driving same issue appeared I drove for about an hour then stopped checked
voltage again while running and it was 12 9 to 13 V if I turn on all of my lights
and air-conditioner full blast it'll jump to 13.2 any suggestions
The computer handles the charging on this rig, if the voltage is dropping that low then it sounds like something is happening with the sensing circuit in the computer. It should not drop below 13.2 volts at idle, battery fully charged.
Only happens after about an hour of driving, is it usually in the ecm and can it just be swapped out?
It's usually a programming error and it is usually cured by a dealer reflash, but sometimes it can't, then it has to be replaced and flashed to the rigs VIN.
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