1997 Pontiac Transport gage

Gauge Inoperative Or Inaccurate Disconnect 12-pin, Gray body connector under vehicle, behind driver seat. Connect Instrument Panel Tester (J33431-B) between 12-pin, Gray body connector terminals No. 3D (Purple wire) and 3B (Black/White wire). Turn ignition on. Set resistance dial to zero ohms. Fuel gauge should indicate EMPTY or below. If fuel gauge indicates EMPTY, go to step 4). If fuel gauge does not indicate EMPTY, go to next step. 1. Using DVOM, check resistance between 12-pin, Gray body connector terminal No. 3B (Black/White wire) and ground. If resistance is not 1-3 ohms, check and repair Black/White wire for open, excessive resistance or short to voltage. If resistance is 1-3 ohms, go to next step. 2. Turn ignition off. Connect fused jumper wire between Gray body connector terminals No. 3D (Purple wire) and 3B (Black/White wire). Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION . Measure resistance between instrument cluster Black connector terminal "D" (Black wire) and ground. If resistance is not 1-3 ohms, check and repair Purple wire between instrument cluster Natural connector terminal "P" and fuel level sending unit connector for an open, excessive resistance or short to voltage or battery. If resistance is 1-3 ohms, replace instrument cluster. 3. Set resistance dial of instrument panel tester to 90 ohms. If gauge does not indicate FULL, check and repair Purple wire between instrument cluster Natural connector terminal "P" and fuel level sending unit connector for an open, excessive resistance or short to voltage or battery. If gauge indicates FULL, go to next step. 4. Vary instrument panel tester and compare to gauge reading. See FUEL GAUGE RESISTANCE . If fuel gauge readings match table, replace fuel level sending unit. If fuel gauge readings do not match table, check and repair Purple wire between instrument cluster Natural connector terminal "P" and fuel level sending unit connector for an open, excessive resistance or short to voltage or battery. 5.