I have heated mirrors but they seemed to have stop working. I pushed the heated mirror button and it lit up for a second and then shut off. I checked the fuse was ok, there was no power in the terminal it plugs into. I don't think it is temperature controlled because it was about 10 degrees , and I don't have a rear window defroster to control it either. Any suggestions? The truck is a 2006 f150 supercrew with 39k miles and always garaged. It has a rear sliding window without defroster. I am having battery drain issues , so maybe there is a short somewhere.2/17/11- found heated mirror circuit had a bad relay.

 

mirrors and rear window are the same button, if its shutting off and its not the fuse there must be a short somewhere most likely, or perhaps one of the wires broke and it cant complete the circuit. how old of a truck?

 

Defrosters are high amperage drawing components when turned on they use most of the amperage put out by the alternator. If u have a charging issue correct that first as it is likely at fault. The defroster is controlled by a module that will turn it off if the PCM senses that alternator output is not enough to run all vehicle components.