Remove the YEL/RED wire (A) from the engine oil pressure switch (B). Check for continuity between the positive terminal (C) and the engine (ground). There should be continuity with the engine stopped. There should be no continuity with the engine running. If the switch fails to operate, check the engine oil level. If the engine oil level is OK, check the engine oil pressure. If the oil pressure is OK, replace the oil pressure switch.

Special Tools Required Oil pressure gauge attachment, 07406-0030000 Oil pressure Gauge, 07506-3000000 If the oil pressure warning light stays on with the engine running, check the engine oil level. If the oil level is correct. Connect a tachometer. Remove the engine oil pressure switch and install the special tools. Start the engine. Shut it off immediately if the gauge registers no oil pressure. Repair the problem before continuing. Allow the engine to reach operating temperature (fan comes on at least twice). The pressure should be: Engine Oil Temperature: 80° C (176° F) Engine Oil Pressure: At Idle: 70 kPa (0.7 kgf/cm2, 10 psi minimum) At 3,000 rpm (min-1): 340 kPa (3.5 kgf/cm2, 50 psi minimum) If oil pressure is NOT within specifications, inspect the oil pump (see step 7 on page 8-10).