Side Mirrors Constantly Heating

[priatelche]

Hi!
I have a problem with my A170 CDI (October 2001). My side mirrors are constantly heating when I switch on the electricity. They become so warm that I cannot touch them! I replaced my right mirror with a new one but the new one is also constantly heating! What may be the problem? Is there any thermo sensor in the mirrors or anywhere in the car that switches on & off the heating of the mirrors? Where is this sensor located in order to change it? Can someone give me a scheme of the wiring of the A-Class or just the wiring of the mirrors? When I remove the mirrors' fuse they stop heating but they stop moving too. I have the idea to mount a switch just on the heating electrical chain but I am unfamiliar with the wiring of the mirrors.
Thank you very much in advance!

[lofty]

The Mb paper work on this one says they are controlled by a thermostate, it may that this has gone defective or may just want re-setting using 'star' diagnostics But remember that's £50 before you turn a wheel. At present I can't see where it's located although i suspect it near the mirror control switch on the dash.

[priatelche]

Thanks. I read a lot on the problem and as much as I saw the thermostate is located in the very mirror. A part of the heater that is located in the glass of the mirror is a thermosensitive element that switches on and off the electric chain. I disagree because I changed one of the mirrors with a new one from the shop and it is still heating. Yet, I managed the problem somehow. I just mounted a miniature switch on the cable that comes from the door to the mirror and now I can switch on and off the heating manually. I thought over the possibility that the heating is controlled by the same thermostate that indicates the outern temperature (the thermometer on the dashboard) but it is working perfectly and shows the real temperature that is 25 - 30 oC at that moment.