I am trying to figure out my heater fan is stuck on constantly. I found the power transistor tye wrapped to the metal of dash where the fins on transisitor were grounding out and making fan stay on. I think it is a bad transistor but cant find one to test at a parts store. I have the 1.5 ohms the manual says you should have between 1 and 2 i think but 1 and 2 are a short to the heatsink fins also it appears when i test so if mounted to frame it is a short to ground and fan runs but not shorted i have no fan or control?

 

UPDATE > It is just pin 1 that I have continuity thru transistor to heat sink fins I need to know if that is right or if the powerr transistor has failed?
Bye the way this is a 2005 TL

 

WOO HOO !! I figured it out. It was the power transistor.
FYI pins 1 and 2 are a short to the heat sink fins on the outside of power transistor and also 1.5 ohms between 1 and 2 dont let it get grounded like mine was or the fan runs constantly. Now anyone want to help me figure out why my clock/climate upper display dosnt work? (with navigation) I have all the voltages measured going in to it anyone got a wire diagram to help me resolve?

 

does this work?

 

I'll give this a 7 and a half year bump.

My car just started doing this. It just constantly blows air on high speed. Turning the system off doesn't help at all. It just keeps blowing. If I manually try to adjust the speed, there's no effect at all.

Is this power transistor fix an easy thing to do? Can you shed some more info on how to do it?

Thanks