Instrument Cluster Dimmer Control Test
- Turn ignition off. Carefully pry dimmer control from instrument panel. 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 Red/Black wire terminal. If battery voltage exists, go to next step. If battery voltage does not exist, check fuse No. 32 (15-amp), located in underhood fuse/relay box. Check combination light switch. See STEERING COLUMN SWITCHES article. 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 Red wire terminal. 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 underdash fuse/relay box. See SYSTEM WIRING DIAGRAMS article in the WIRING DIAGRAM section.
- Turn ignition switch and combination switch off. Using an ohmmeter, check continuity between 3-pin connector Black wire terminal 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.