Tach does not work at start up
- Thread starter Mike G.
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Probably is a bad electrical connection in the tachometer system.. There is a pick-up sensor on the aft, 10 O’clock position on the flywheel housing.. one wire is blue with a maroon stripe and the other is kinda pink.. Those push connectors get loose/dirty and do exactly what you describe .. the other place to look is for a loose/dirty connection in the power supply wires to the tach instrument itself. Good luck
No, your regulator senses a full battery (assuming you've been plugged in) and doesn't turn the alternator on until it senses a load. Watch your voltmeter and see what it does.
I have a similar problem on on 1991 Yanmar 4JH2-TE 62 HP on my Hunter Passage 42. My tachometer moves very slowly--it takes maybe 30 seconds to slowly get up to where the RPM really is. This slowness continues while both increasing and reducing engine speed, and it doesn't stop. I know that this "tired" tachometer isn't due to the voltage regulator control, with which I am familiar. The tachometer lags the changes in RPM consistently and slowly, not like the cut-in and cut-out of the alternator. I've wondered for quite some time what I could do about it. Claude, I'll take a look at those connections. Thanks for that tip. Absent that being the problem, any other ideas?
Stu, I'd agree, except that the belt is tight and the alternator is charging exactly as it should. I wonder if a tach can go bad this way? As opposed to either working or not working at all?belt, 'cuz electronic signals never take that long!
Typical with long-time-in-service Yanmar control panel tachometers .... corrosion in the 'pointer' bearings. Test: After starting and the needle doesnt move, next time 'rap' the edge of the tach with a solid plastic 'object' - each 'hit' will advance the needle until you get a constant max. indication.
Either replace the tach or take it to an 'instrument tech' who will 'clean and repair' the bearings, etc. A weatherproof clear 'cover' over a Yanmar engine control panel will save a lot of 'grief' with corroded, etc. instruments, starter buttons, key switches, etc.
Either replace the tach or take it to an 'instrument tech' who will 'clean and repair' the bearings, etc. A weatherproof clear 'cover' over a Yanmar engine control panel will save a lot of 'grief' with corroded, etc. instruments, starter buttons, key switches, etc.
Thanks, Rich. That sounds like the problem. It has always seemed to behave more like a mechanical issue than an electrical one. It also makes sense when I consider how often I've seen rain water get in behind the cover plate (through the opening cut for the key and access to the light switch toggle).
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