Hi folks... The tachometer on my '87 Cat 30 gets twitchy and will jump from 700 rpms to 1500 and basically bounces all over the spectrum. I can tell where my rpms are by the engine sound and where the tach spends most of it's time... Should I be looking at replacing the sending unit on the engine (if there even IS one) or get a new tach itself? It's more annoying and anything, but I'd prefer having a good reading all the time. Suggestions?? Thanks Jim
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Tach Twitch
Jim You wrote: "Should I be looking at replacing the sending unit on the engine (if there even IS one) or get a new tach itself?" The tach works off the alternator, not the engine. Check all your connection at the alternator and the back of the instruments, including the ground wires, first before doing anythine else. If you alternator is not working properly, or if your batteries are completely full and your alternator doesn't need to put out any juice, that may be causing the problem. Check those first before buying anything. Stu
Jim You wrote: "Should I be looking at replacing the sending unit on the engine (if there even IS one) or get a new tach itself?" The tach works off the alternator, not the engine. Check all your connection at the alternator and the back of the instruments, including the ground wires, first before doing anythine else. If you alternator is not working properly, or if your batteries are completely full and your alternator doesn't need to put out any juice, that may be causing the problem. Check those first before buying anything. Stu
ok..thanks
Stu... I'll check the wiring. I never knew the tach operated off the alternator. You learn something new every day!!
The boat is usually connected to shore power and the battery charger is always on....so it's very possible that with the exception of recharging the batteries after the engine start drain, the alternator is indeed not producing power...but I would think the tach would be able to accomodate that situation...?? Jim
Stu... I'll check the wiring. I never knew the tach operated off the alternator. You learn something new every day!!
The boat is usually connected to shore power and the battery charger is always on....so it's very possible that with the exception of recharging the batteries after the engine start drain, the alternator is indeed not producing power...but I would think the tach would be able to accomodate that situation...?? Jim- Status