Cutlass Supreme V6-3100 3.1L MFI VIN M (1994)
Oil Pressure Gauge: Service and Repair
Disconnect the oil pressure gauge lead from the sending unit, connect a 12 volt test lamp between the gauge lead and the ground and turn ignition on.
If test lamp flashes, the instrument voltage regulator is functioning properly and the gauge circuit is not broken. If the test lamp remains lit, the
instrument voltage regulator is defective and must be replaced. If the test lamp does not light, check the instrument voltage regulator for proper ground
or an open circuit. Also, check for an open in the instrument voltage regulator to oil pressure gauge wire or in the gauge itself. If test lamp flashes
and gauge is not accurate, the gauge may be out of calibration, requiring replacement.