Ok, after downloading the WSM manual for my M108SHDC tractor, it turns out the input signal for the tachometer comes from the engine rotation sensor and comes into the meter panel on pin 36 yellow/blue wire. The sensor is located on the left upper of the rear differential. It does not get any kind of signal from the alternator. I replaced the defective sensor and now my tachometer is working fine.Downloaded the WSM for the M018s from www.kubotabooks.com
Signal is a pulsating DC signal ( probably 0 to +12v ) from alternator going to the 'meter panel' through a wht/grn wire that's joined to a wht/yel wire.
This is why the WSM always wins the info game!Ok, after downloading the WSM manual for my M108SHDC tractor, it turns out the input signal for the tachometer comes from the engine rotation sensor and comes into the meter panel on pin 36 yellow/blue wire. The sensor is located on the left upper of the rear differential. It does not get any kind of signal from the alternator. I replaced the defective sensor and now my tachometer is working fine.