Need some OBS silverado help
Reply #4 –
The gauge is powered up by the cluster power keyed from the ignition. It should also have a charge light some do. And a check gauges warning system. Once again do some voltage readinga at various loads to see if your ALT is starting to go. Load the alt down with high beams heater on high and bring the engine up to APP 1400 RPM'S and read the voltage. Once again should be over 13.9 and 14.6 +or-