STEP 1. Measure the power supply voltage at engine oil pressure switch harness side connector.
(1) Disconnect the engine oil pressure switch connector measure at the harness side.
(2) Turn on the power supply mode of the electric motor switch.
(3) Measure the voltage between terminal OPSW and ground.- The voltage should equal 12V starter battery positive voltage.
(4) Turn off the power supply mode of the electric motor switch.
Is 12V starter battery positive voltage (approximately 12 volts) present?
Go to Step 4. Go to Step 2.