When the ignition switch is in the RUN position, voltage is applied from the IP fuse block, fuse 21 to the electronic climate control module.
When the defogger switch is pressed, voltage is momentarily applied to the defogger request input of the solid state timer. The timer closes the internal contacts from terminal D14 to terminal C10 of the electronic climate control module. The following actions then occur:
- The ON indicator of the switch lights.
- The coil of the defogger relay is grounded using CKT 193 (WHT).
The defogger relay coil is supplied with voltage through the IGN E fuse of the underhood fuse block.
When the relay contacts close, voltage is applied from the defogger relay terminal 30, to pin 87 through both of the following fuses:
| • | The RR DFOG fuse to CKT 1093 |
| • | The HTD MIR fuse to CKT 2267 |
These circuits supply the following components:
| • | The rear defogger grid (finding ground at G420) |
| • | The left mirror grid (finding grounds at G200 and G201) |
| • | The right mirror grid (finding ground at G202) |
The solid state timer within the electronic climate control module controls the amount of time that the internal contacts are closed.
The defogger cycle runs for 10 minutes when the following conditions exist:
| • | The ignition switch is turned to the RUN position. |
| • | The rear defogger switch is turned to the ON position for the first time. |
Further operation results in 5 minute defogger cycles. The defogger cycle resets to 10 minutes when the ignition switch is turned to the OFF position and then turned to the RUN position.
