I just purchased a 1991 RX7 non-turbo and I am trying to fix the gauges. The motor was replaced with a 1991.

The fuel, temp and oil gauges do not work. The gauge lights work behind the gauges. The battery gauge works, but shows a high reading. I checked the METER and ROOM fuses and they are OK.

 

Several possibilities:

ONE: bad solder joint on the trace that feeds those gauges (I am not sure if this is possible with the volt meter functioning).

TWO: All three sensors are not connected on the new engine (I doubt you missed them all, especially the fuel gauge, since that should never have been disconnected).

THREE: One of the harness connectors is improperly inserted (if the engine runs, this is not likely, this also does not explain the fuel gauge).

So far number ONE looks most promising. Please check your sensors (Oil pressure is the easiest, right below the oil filter.)

After you double check the connections (unless you already have) I can dig out my instrument cluster and follow traces.

I do have an extra instrument cluster, so I can check without removing mine.

 

ok today the check engine light went on.. i dont know if that has any connection to the gauge problem