Hello All,

I have my old truck 86' f150. One of the problems when i'm driving on a humid cold day is that the windows tend to fog up. If I turn on the defrost the problem will slowley go away. However, that means I must wear a heavy coat and gloves to keep warm. The blower seems to blow nice and fast in air conditioning mode. I suppose it is the resistor that slows it down for defrost mode.

Would anybody have any suggesstions. I am thinking about putting in a bypass wire for the resistor. I also thought about getting a new faster blower unit from a scraped vehicle. Does anybody have any ideas or suggesstions??

R. Ellis

 

Blower motor should not change speeds between MODES. It sounds like maybe a door inside the Plenum Case is broke causing this difference in speed. Or air movement. One thing that helps defrost the windows is A/C system they use this system as a dehumidifier. So make sure the A/C system is working.