Alternator, Voltage Regulator / Tachometer Question.
I have a Pilgrim 40 with a 100 hp Westerbeke main engine.
I am having trouble with my tachometer. The needle fluctuates back and forth while running my engine. Sometimes it is steady, but most of the time it bobs back and forth for 0 – 1500 RPM (or that speed my engine is running). The weekend while moving slowly, I could easily hear my engine running. Every time the tachometer would work the engine would change tunes (you know what I mean) like a slight load was being put on the engine. Then when the tachometer would stop working the engine would change tunes again.
Could this unusual tachometer operation be related to a bad alternator or voltage regulator?
Pilgrim 40 Hull #18