Idiot lights and Buzzer

Oct 15, 2012
8
Hunter 290 Panama City
I am replacing the buzzer as it is intermittent. Sometimes will work at key on, sometimes when testing with switch, mostly sounds like a clock ( tick tick tick). Diodes gone bad. My question is about the idiot lights. Oil and temp work at key on and test but the Gen light never does. I checked connections and continuity, voltage and all looks good, maybe. I can get the light to turn on by bypassing and hot wire. Is it possible that something at the alternator is bad? I have checked and it is charging. forgot how many amps out put, but it was good. Off subject, the PO must have been Italian cause all the wiring looked like spaghetti. AND he must have loved it ALOT. hahaha.
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
Check the grounds on the wiring harness. None of my idiot likes worked. I changed the ground wire at the panel and now they all light up, except the alternator which isn't connected to the harness.

Do you have a Yanmar?
 
Oct 15, 2012
8
Hunter 290 Panama City
Yanmar 2GM20F-YU You say the Alt is not connected. I traced the wiring per the schematic and cant locate them at the alt. Any hint as to what the connection looks like? Thanks!
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
Yanmar 2GM20F-YU You say the Alt is not connected. I traced the wiring per the schematic and cant locate them at the alt. Any hint as to what the connection looks like? Thanks!
Some Yanmars do not use an alternator tap for the Tach. Instead they use a magnetic sensor that counts the teeth on the flywheel. It looks like a large bolt screwed into the bell housing near the starter. There will be 2 wires leading from it to the wiring harness.

There are 3 places the tach can fail, the head, the sensor, or the wiring. Start with cleaning the connections. If that doesn't work test the sensor, the test should be in the shop manual. It should produce several volts of alternating current and there is a specified level of resistance. If all that tests out OK then the issue is likely the head.

The parts are not inexpensive.

A shop manual for the GM series is available online. Spend some time with a good search engine.
 
Oct 15, 2012
8
Hunter 290 Panama City
I've got the shop manual from Yanmar. My question was about the Alternator / charging light not lighting at the instrument panel when I use the momentary switch for testing. I also just bought a new Buzzer from Hunterowner. I replaced the Tach two years ago and all is fine there. The tach runs independent of the Buzzer and warning lights. I have a amp meter tied into the alternator so I can monitor. Just wanted the idiot light to work with the buzzer IF things goes sideways. Thanks