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Q: How do I know if the rear defrost module is bad?

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Rear defrost doesn't work but the light does come on

My car has 11300 miles.
My car has an automatic transmission.

A: Hi there. If you checked the fuse, defrost...

Hi there. If you checked the fuse, defroster switch, main power tabs and the wiring but the defroster still does not work, then It is time to take a look at the relay. The defroster relay is normally located under the dash. Some installations combine the timer and relay in one unit. Jump the relay defroster wires with a jumper wire and if the defroster works then the problem is the relay. Remove the unit and replace it with a new one. If you need further assistance with diagnosing the rear defroster, then seek out a professional, such as one from Your Mechanic, to help you.

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