Test I: Oil Pressure Indicator Inoperative

Turn ignition switch to LOCK position. Disconnect oil pressure switch harness connector C115. Connect a fused jumper wire between ground and terminal No. 1 at oil pressure switch harness connector C115. Turn ignition switch to RUN position. If oil pressure light illuminates, go to next step. If oil pressure light does not illuminate, go to step 3.
Manually check engine oil pressure. See appropriate article in ENGINES. If oil pressure is within specifications, replace oil pressure switch. If oil pressure is not within specifications, repair engine mechanical problem as necessary.
Turn ignition switch to LOCK position. Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Disconnect instrument cluster harness connector C266c. Measure resistance of Red wire between terminal No. 1 at oil pressure switch harness connector C115 and terminal No. 9 at instrument cluster harness connector C266c. See Figure. If resistance is less than 5 ohms, replace instrument cluster printed circuit. See PRINTED CIRCUIT under REMOVAL & INSTALLATION. Retest system. If resistance is 5 ohms or more, repair open in Red wire.