so i just bought my car sunday and the guy put an aftermarket rpm gauge in and it was working fine
like last night it was working perfect and now its not working at all, not reading anything
i'm not sure what it is and don't know how to check it especially since i didn't install it
could it be a fuse even though its aftermarket? but all my other gauge are working...
i did wash my car today with my hood off to clean the engine bay a bit cause it was so dirty but i think that might have something to do with it....

let me know what you think....

 

just carry the car to your local auto tech or garage.

 

Check under the hood, on the dizzy there is a blue wire, that is the wire that reports RPM back to the ECU/aftermarket tach. Start there, the wire probably wasn't properly soldered and heat wrapped, probably just twisted and wrapped in tape.

 

MM&Y of car please?

Make and model of tach? 94