Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Check for B+ on the Orange wire at the connector to the alternator. Verify the PCM is sending out 5 volts on the Red wire at the alternator.
We have seen a lot of alternators with the wrong regulators installed in them which will not turn on with the 5 volts that the PCM puts out. If you get multiple alternators that don't work, try a different supplier. Sometimes AC delco is the only option.
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5 volts comes from the PCM. If it's dropping out then the PCM might be faulty.
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