Re: 2QM20 Tach wiring
It's a Faria IS0015 Variable Ratio Alternator and Switching Diesel Tachometer. It will be accurate on the alternator, but the problem is you need some kind of reference tachometer to dial it in. I have this cheapo strobe tach to use as a reference to set it up with.
Bashing about on Lake Ontario and Beyond
"Ariel" '79 Endeavour 32