Rear Window Defogger Switch
- Rear window defogger switch is located on the A/C switch assembly. See Figure. To test the defogger timer operation, disconnect 10-pin electrical connector from A/C switch assembly. Using jumper wires, connect battery voltage and ground to terminals No. 1 and 3 on A/C switch assembly. See Fig 1. Also, connect 3.5 watt light bulb between positive battery terminal and No. 5 on A/C switch assembly. See Fig 1.
- Depress rear window defogger switch to ON position. Check that indicator light in rear window defogger switch and light bulb turn on for 12-18 minutes and then turn off. If operation is as specified, disconnect battery and go to next step. If operation is not as specified, disconnect battery. Replace rear window defogger switch.
- Note electrical terminal identification on wiring harness side of 10-pin electrical connector from A/C switch assembly. See Fig 2. Check for continuity and proper voltage between specified electrical terminals on 10-pin electrical connector for A/C switch assembly for rear window defogger switch with electrical disconnected under specified conditions. See A/C SWITCH ASSEMBLY SPECIFICATIONS table. If continuity and proper voltage exist, go to next step. If continuity or proper voltage does not exist, repair wiring harness and electrical connector on electrical circuit as necessary and check operation of rear window defogger. See WIRING DIAGRAMS in REAR WINDOW & MIRROR DEFOGGER article.
- Reinstall 10-pin electrical connector on A/C switch assembly. Check for proper voltage between specified electrical terminals on 10-pin electrical connector for A/C switch assembly for rear window defogger switch under specified conditions. See A/C SWITCH ASSEMBLY SPECIFICATIONS table. If proper voltage does not exist, replace rear window defogger switch. If proper voltage still cannot be obtained, it may be necessary to check wiring harness and electrical connectors for rear window defogger. See WIRING DIAGRAMS
in REAR WINDOW & MIRROR DEFOGGER article.A/C SWITCH ASSEMBLY SPECIFICATIONS
Condition & Tester Connection Condition Result With 10-Pin Electrical Connector Disconnected From A/C Switch Assembly, Check Between Body Ground & Specified Terminal 3 Constantly Continuity 5 Ignition Switch In LOCK Or ACC Position No Voltage 5 Ignition Switch In ON Position Battery Voltage With 10-Pin Electrical Connector Installed On A/C Switch Assembly, Check Between Body Ground & Specified Terminal 5 Ignition Switch In ON Position & Rear Window Defogger Switch In OFF Position Battery Voltage 5 Ignition Switch In ON Position & Rear Window Defogger Switch In ON Position No Voltage Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002