Tach hookup

I just got my 67 fairlane from the original owner and his son started to install a kmc tach in the dash for him but didnt know how, he didnt keep the instructions, and i was wondering if anyone knew where the wires have to go, theres 4 wires and im assuming one goes to the coil and one to neg batt but idk about the rest, any help is great thanks

Don't know the KMC, but the tachs I've used are usually;

Green to coil
Red to switched power
Black to ground
Blue to instrument lighting

Originally Posted by QuicknDirty

Don't know the KMC, but the tachs I've used are usually;

Green to coil
Red to switched power
Black to ground
Blue to instrument lighting

That is same for my monster tach . I hooked it up as such but had a problem . My dist was electronic and tach was off 500 rpms .