2001 Silverado 1500: volt gage fluctuates

[RayInAlaska]

I will start with an apology in case I am not posting in the right forum.

My 2001 Silverado's volt gage fluctuates from 14 to 16 volts when the engine is idling or when I am driving the truck. I replaced the original alternator with a new one just because the old one had a lot of use on a truck that already had around 111,000 miles.

The new alternator worked wit a hitch for over two years until the volt gage pointer started moving or fluctuating as explained above. I assumed that either the voltage regulator (or the rectifier) was malfunctioning, so I replaced the alternator with a new one since it is under a lifetime warranty, but the problem continues, even with this last brand new alternator.

When I check the alternator's output to the battery with a Fluke multimeter, or with a digital battery/alternator tester I have, the alternator is working perfectly at 13.2 VDC base charging voltage, and a maximum of 14.5 (no fluctuations whatsoever on the meter and tester, just the volt gage in the dash).

I assume that the voltage regulator in inside the alternator, and that the two new alternators aren't causing the problem. Do you have any idea what could be causing the volt gage to fluctuate like that? The only plug on the alternator is located right on top, and has two wires that run toward the trucks cab. I imagine that these two wires lead to the volt gage. I have checked the plug contacts, and everything seems to be clean and solid, but I haven't been able to trace the wires all the way to the gage.

Thanks in advance!