Test D: Oil Pressure Gauge Inaccurate Or Indicator Is Always On
WARNING: This page is about a different car, the 2002 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition switch to LOCK position. Disconnect engine oil pressure switch harness connector C103. Turn ignition switch to RUN position. Connect fused jumper wire (5-amp) between engine oil pressure switch harness connector and ground. Oil pressure gauge should indicate normal oil pressure with jumper wire connected and no oil pressure with jumper wire disconnected. If oil pressure gauge operation is not as specified, go to next step. If oil pressure gauge operates as specified, replace engine oil pressure switch.
- Turn ignition switch to LOCK position. Disconnect instrument cluster 20-pin harness connector C220a. Measure resistance in White/Red wire between engine oil pressure switch harness connector C103 and instrument cluster 20-pin harness connector C220a terminal No. 20. Measure resistance between instrument cluster 20-pin harness connector terminal No. 20 (White/Red wire) and ground. See Figure. Resistance should be 5 ohms or less between instrument cluster 20-pin harness connector and oil pressure switch harness connector, and more than 10 k/ohms between instrument cluster 20-pin harness connector and ground. If resistance is as specified, go to next step. If either resistance is not as specified, repair open or short to ground in White/Red wire between oil pressure switch harness connector and instrument cluster.
- Disconnect all instrument cluster harness connectors. Inspect harness connectors for corrosion and pushed out pins. Connect all instrument cluster harness connectors, ensuring they are connected correctly. Operate system and verify if concern is still present. If concern is still present, replace instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. If concern is not present, system is operating correctly at this time.