Instrument Cluster Dimmer Control Test
- Turn ignition switch to OFF position. Remove driver's switch panel, located left of steering column. Disconnect dimmer control unit 3-pin connector. Check connector for open, loose or disconnected terminals. If terminals are bent, loose or corroded, repair as necessary and recheck system. If terminals are okay, go to next step.
- Turn combination light switch to ON position. Using a voltmeter, measure voltage at 3-pin connector terminal No. 1 (Red/Black wire). If battery voltage exists, go to next step. If battery voltage does not exist, check fuse No. 21 (15-amp), located in underhood fuse/relay box. Check combination light switch. See STEERING COLUMN SWITCHES article. Check taillight relay, located in underhood fuse/relay box. Check for poor connections or open in Red/Black wire between dimmer control unit and taillight relay located in underhood fuse/relay box.
- Turn combination light switch to ON position. Using a fused jumper wire, ground 3-pin connector terminal No. 2 (Red wire). If instrument panel indicators illuminate at full brightness, go to next step. If instrument panel indicators do not illuminate at full brightness, check for poor connections or open in Red wire between dimmer control unit and front foglight/main cruise control main switch. See appropriate WIRING DIAGRAMS in SYSTEM WIRING DIAGRAMS article in the WIRING DIAGRAMS section.
- Turn ignition switch and combination light switch to OFF position. Using an ohmmeter, check continuity between 3-pin connector terminal No. 3 (Black wire) and ground. If continuity exists, replace dimmer control unit. If continuity does not exist, check for poor connections or open in Black wire between dimmer control unit and ground connection located under hood release.