Hello, do you have voltage or Ground at the grey wire on the Alternator? The bulb in the Cluster is provided a ground if the alternator stops charging. Also check that the Fusible links are not burned up inside. Do a voltage drop test from Battery Positive to the B+ post on the alternator, what reading do you get with your meter set on 20vdc scale? Check it with the truck running. Also check the A wire to the Battery positive post. You should have very little voltage drop on the positive side of the circuit.
be sure to check the fuses as well in Junction box, behind the passenger side kick panel.
the bulb might be burned out, or there could be an issue with the Cluster.
The 2nd diagram below explains the voltage drop testing for the positive side and ground side from the Alternator case
https://www.2carpros.com/articles/how-to-check-a-car-alternator
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May 27, 2023 at 4:20 PM
