
I have a 2002 6l 4x4 extended cab truck. I have changed the Altinator twice and the battery once. The problem is when driving and the RPMs reach 2000, the voltmeter on the dash drops from 15 to around 12to13, the head lights and dash lights dim. The diming lasts from a couple seconds to a couple of minutes as long as the RPMs stay around 2000. If the RPMs drop below 2000 to volt reading returns to 14to15. All connections are clean and tight. any ideas as to what's going on?
I have been told that the volt meter should anly read around 13. Is this true?
Thanks for any help.