Diagnosis and Part Selection Advice:
The oil pressure switch is a dual purpose device that supplies power to the fuel pump as well as the signal for the oil pressure gauge. A faulty oil pressure switch can cause the vehicle to die intermittantly, not run at all, or gauge to malfunction. Also, this sensor will often fail to power the fuel pump while still operating the gauge normally. Failure is often intermittant, commonly during low pressure condions like warm/thin oil and lower rpm's. Diagnosis can be made by back probing the connector on the oil pressure switch with a voltmeter.
These switches are of poor quality. They are made mostly of plastic and fail often. I have tried Duralast and AcDelco
oil pressure switches and the AcDelco
has been more durable.
Repair / Installation tips:
You will need a special socket for this sensor, it should be available at most auto parts stores. A regular socket might work if it was very deep, but I have not tried this. Also, be careful of the fitting that the sensor threads into, it is a small brass fittings that can be easily damaged.