Ford Full-Size Vans 1989-1996 Repair Guide

Oil Pressure Sender-Indicator Lamp Type


See Figures 1, 2 and 3

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Fig. Fig. 1: Common oil pressure switch locations-4.9L, 5.0L and 5.8L engines

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Fig. Fig. 2: Some engines have the oil pressure sender mounted on a fitting-5.0L/5.8L engines

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Fig. Fig. 3: Oil pressure switch mounting-7.3L diesel and 7.5L gasoline engines. (Note that the adapter is only used on diesel engines)


A single terminal oil pressure switch is used on vehicles equipped with an oil pressure lamp.

If the pressure is detected to be at an unsafe level, a red indicator lamp will glow on the dashboard. The light should come on when the engine is off but the ignition is in the RUN position. Once the engine is started, the light should go out.

The lamp is connected between the oil pressure switch unit (mounted on the engine and the coil terminal of the ignition switch.


  1. Turn the ignition to the RUN position with the engine not running. The indicator lamp should come on.
  3. If the indicator lamp does not come on, disconnect the wire from the oil pressure switch terminal and ground the wire.
  5. If the indicator light comes on, the pressure switch is inoperative. Replace the switch.
  7. If the indicator light fails to come on, either the bulb is burned out, there is no power to the bulb, or the circuit is open somewhere between the bulb and the oil pressure switch.
  9. If the lamp stays on with the engine running and the engine has adequate oil pressure, disconnect the wire to the switch. If the lamp goes out, replace the oil pressure switch. If the lamp does not go out, correct the short in the wiring between the switch and lamp.


The pressure switch used with the oil pressure warning light is not interchangeable with the sending unit used with the oil pressure gauge. If the incorrect part is installed the oil pressure indicating system will be inoperative and the sending unit or gauge will be damaged.

  1. Unplug the connector at the unit and unscrew it from its mounting.
  3. To install the unit, apply pipe sealant or Teflon® tape to the threads of the new switch and screw it in to its mount. Tighten it to 8-18 ft. lbs. (11-24 Nm).
  5. Connect the wiring to the unit.
  7. Run the engine and check for leaks and proper operation.