Lights On Reminder System Input Test

Remove underdash fuse/relay box. See UNDERDASH FUSE/RELAY BOX under REMOVAL & INSTALLATION. Remove driver's multiplex control unit from underdash fuse/relay box. See Figure . Check driver's multiplex control unit connectors for loose, damaged or corroded terminals. If problem exists, repair as necessary. If problem does not exist, go to next step.
Check continuity between ground and fuse/relay box socket connector terminal A14. See Figure . Open driver's door. If continuity exists with driver's door open, go to next step. If continuity does not exist with driver's door open, check for open in Green wire between driver's door switch and underdash fuse/relay box. Check driver's door switch. See WIRING DIAGRAMS . Repair as necessary.
Turn ignition on. Measure voltage between ground and fuse/relay box connector terminal A13. See Figure . If battery voltage exists, go to next step. If battery voltage does not exist, check for blown fuse No. 13 (15-amp) in underdash fuse/relay box. Check for open in underdash fuse/relay box between fuse No. 13 holder and driver's multiplex control unit connector. Repair as necessary.
Turn headlights on. Measure voltage between ground and fuse/relay box terminal A2. See Figure . If battery voltage exists, lights-on reminder inputs to driver's multiplex control unit are okay. If battery voltage does not exist, check for blown fuse No. 10 (15-amp) in underdash fuse/relay box. Check combination switch. See STEERING COLUMN SWITCHES article. Check for open in underdash fuse/relay box between fuse No. 10 holder and driver's multiplex control unit connector. Repair as necessary.