Originally Posted by RickB
Another question if the shop manual has errors. The only heated system of the three in this thread covered is the mirrors, and it says that the heaters are on whenever the ignition is on. By the schematic, it could be 110F in the shade and they will be on if the ignition is on.
Sounds like we need to check this with a volt meter! Personally, I find it hard to believe that the heaters would be on all the time. That just doesn't make sense because it would contribute to a premature failure in the heaters and cause an undue load on the electrical system. I always figured that they would a) come on automagically when the outside temperature sensor registered below some pre-determined threshold, or b) they came on with either the rear window defroster or when the HVAC selector was set to defrost the front window, or c) some combination of the above.