- To test the normally closed oil pressure sender, disengage the electrical connector and measure the resistance between the switch terminal (terminal for the wire to the warning lamp) and the metal housing. The ohmmeter should read 0 ohms.
- To test the sending unit, measure the resistance between the sender terminal and the metal housing. The ohmmeter should read an open circuit (infinite resistance).
- Start the engine.
Once again, test each terminal against the metal housing:
- The oil pressure switch terminal-to-housing circuit should read an open circuit, if there is oil pressure present.
- The sending unit-to-housing circuit should read between 15-80 ohms, depending on the engine speed, oil temperature and oil viscosity.
- To test the oil pressure sender only, rev the engine and watch the ohms reading, which should fluctuate slightly (within the range of 15-80 ohms) as rpm increases.
- If the above results were not obtained, replace the sending unit/switch with a new one.
REMOVAL & INSTALLATION
See Figure 1
The oil pressure sender is located in the rear center of the block, facing the firewall. The sender is slightly below and toward the passenger' side of the vehicle from the knock sensor.
- Disconnect the negative battery cable.
- Detach the sender electrical connector.
- Using a 3 inch long wobble drive extension and a 3 / 4 inch (19mm) crow's foot, carefully loosen and remove the sender from the engine block.
If it is too difficult to access the sender from the engine compartment, raise and support the vehicle safely, then loosen and remove the sender from underneath the vehicle.To install:
- Install the oil pressure sender in the engine block and tighten to 26 ft. lbs. (35 Nm).
- Attach the oil pressure sender's electrical connector.
- If raised, remove the supports and carefully lower the vehicle.
- Connect the negative battery cable.