i bought this tach used. it has a red, black, green and white wire. can anyone tell me where they all go?

 

well, red is power, black would be a ground, and one of the other ones is your signal wire. You can grab that from the distributor, or break out the manual and see what wire is from the ecu to the dash, and you can hook into that one also, i prefer that way personally.

 

I think white is for the lights, and the green is signal. Just a guess though. Can anyone verify that?