Ok, so-- I went to get my truck back from sub zero temperatures and the blower doesnt work. I thought, oh, probably the fuse. Replaced the fuse for the blower behind the glovebox and the blower has only 1 speed now--all the way on. Anyone have any experience with this problem? should I replace the switch assembly or the blower assy? or both!

let me know, im very cold!

T

 

Check the resistor coils. They are located near the blower motor. They look like little coiled springs. If they appear to be broken then installing a new set will fix you problem. When the heater is all the way on, it uses direct power to the blower motor. When it is on a slower speed, the power goes through one of the resistors to slow it down. I would doubt that your problem is in the switch. The blower motor is probably fine because it works at full speed. If the resistors are not broken then I think you should check the relay. I am not sure exactly how it is wired without looking at a wiring diagram first. Go to www.autozone.com if you do not have a repair manual to find one.

 

you nkow whats wired? my truck had no heater for awhile... then a couple weeks later, i turned it on, and it was all on.. no middle speed..... then a week later it was back to normal... i dont get it...

 

I looked at a wiring diagram of your heater and it appears that the resistors are linked together. If the third highest speed resistor breaks then none of the slower speeds will work.

 

where are the resistors? are they under the dash, or behind the glove box by the blower ( or somewhere else )

Thanks

 

They are near the blower motor, toward the firewall and the driver's side. This site should give you some information:

http://www.4crawler.com/4x4/CheapTricks/Blower.shtml

 

yep, that was it! thanks supernerd

 

No problem. That is what this site is for.