ENGINE AR 2666278 - Caterpillar

procedure tests the engine oil pressure switch for correct operation.
Turn the ignition switch to the ON, but do not start the engine. The warning light for low engine oil pressure should turn on. If the warning light does not turn on, check the electrical circuit to the warning light and the engine oil pressure switch for shorts or an open circuit. Check the bulb for the warning light for damage.If the circuit is correct, replace the engine oil pressure switch. If the circuit is repaired or if the engine oil pressure switch or warning lamp are replaced, repeat this Step in order to ensure that the warning light turns on.
Remove the engine oil pressure switch from the cylinder block. Disconnect the wire connector on the wiring harness from the engine oil pressure switch. Use a 12 volt battery as a power source. Connect the terminals of the battery, the engine oil pressure switch and the leads of the 6V-7070 Digital Multimeter in series. Measure the current through the engine oil pressure switch.
The current should be 0.30 to 0.40 amperes. If the current through the engine oil pressure switch is greater than 0.42 amperes, replace the engine oil pressure switch.