Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Description & Operation
Rear window defogger system consists of rear window defogger switch, rear defogger grid and heated mirrors (if equipped). Rear defogger switch is integrated into Heating Ventilation Air Conditioning (HVAC) controller which is located in center of instrument panel.
Ignition switch must be on to operate rear window defogger system. When rear window defogger switch is pressed, timer relay allows current to flow to grid and mirrors for 10 minutes, then stops current flow. Each time rear window defogger switch is activated after initial activation, timer relay will allow current flow to grid and mirrors for 5 minutes. If ignition is turned off then back on, timer relay resets to 10-minute cycle. Any time rear window defogger switch or ignition is turned off, current stops flowing to grid and mirrors.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.