[RayInAlaska]

Originally Posted by biketopia

odd are it's the gauge (stepper) motor. They do fail and or get sporadic, usually it's the tach or speedo put all of them are known to have issues since it's the same motor. There's companies online that will refurb your dash or you can do it your self. There's lots of how-to info online and the motors are cheap enough on ebay or amazon. If you have a scan tool that can monitor some data like voltage that will tell you what the ECU and seeing and if it's staying steady and the gauge is moving around that's a pretty solid confirmation your gauge motor is on it's way out

I appreciate your response. As I mentioned above, I used both a very accurate Fluke multimeter to check the alternators output, and also an alternator/battery tester, and the alternator output was correct and steady, while the gage fluctuated. The alternator is brand new, and it replaces another alternator that was under warranty because I thought its rectifier (or maybe the voltage regulator) was malfunctioning. Anyway, I will see if I can repair the gage; otherwise I will leave it alone until the next summer.

Thanks again!