In order for the rear window defogger to activate must the temperature be below a certain number? I'm guessing about ten years ago I just couldn't get the small LED to light up after replacing all of the bulbs in the HVAC head. Later, on a cool damp night when I needed the thing to actually work it did and so did the LED on the HVAC control.
I just finished replacing the bulbs again in that dual HVAC unit and I can't get the defogger LED to light up, but then it's a very nice 70 degrees. I did an extensive internet search on the subject and found a vague recollection like mine about temperature being a factor in order for the thing to work. Am I right about this or should I be shopping for a new head? Any way to test it?
Yours,
Bluemill
2000 coupe, 6 speed, 124,000 miles
