Tachometer Testing
 

Can anyone tell me how to test whether a tachometer is good or not other than instaling it in a car? My tach stopped working and I'm trying to determine if it is a wiring or a tach problem. I got a replacement and it doesnt work either. I am getting +12 volts to the + terminal, a ground to the - terminal and a voltage signal that varies with RPM to the middle contact. Does anyone know what goes "bad" when a tach quits working?

Thanks,

JB

I'm in the same boat. I'm thinking of taking my tach apart to see if anything is obvious.

I checked my wiring by connecting a digital multimeter/tach to the lead that plugs into the tach (black/purple wire).