Battery guage on my 2006 Envoy just went past 19 volt mark. Drops a little when all electrial items on. Does not drop when stopped and reetarted. Mike in Michigan
Perform your test first, might be just your gauge?
Or what would cause this to happen would be the voltage regulator in the alternator. Check the voltage at the battery when running like Tom says, there should be like 14.5 to 14.7 DCV at the battery if the alternator is working properly.
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