My 06 Quad cab, 6 sp, Bighorn Edition has had problems with the AC/Heater fan since last summer. I did a search but didn't find my problem. Sometimes the fan comes on and sometimes it doesn't. It stopped last June while on AC and after a few days it worked again. The light on the AC button doesn't go out when you turn the fan to OFF. The flapper seems to work between defrost/floor/vents. It has been working fine this winter until Yesterday and now nothing comes on. There is heat from the vents when the truck is going at speed, but no fan???? Is there a circuit breaker somewhere, or is it the fan that needs to be replaced, or something else? Thanks, Stan

 

If anyone else knows anything about this problem, I too would like some info. That describes exactely what happend to my 07 during the summer two years ago, but has not occurred since then.

 

the fan is working the air vent doors get blocked because the design is very poor they break and hang up. dont go rotating the dials on the heater/fan/ temp settings rapidly. you will be disappointed when it breaks its called the recirculating door now that i think about it. do a search on it

 

A couple of things can cause this. The most common is burnt wires at the ignition switch or the ignition switch itself. Second is the blower motor is toast. I post on these threads every winter it seems......LOL Most of the trucks have a good bit of miles on them that have this issue.

 

Ditto that. Late 06 and up power the fan off the tipm. On earlier trucks the fan motor gets + power directly from the ignition switch, and several folks have found charred wires/switch.

The speed control is on the negative/ground side of the motor and completes the circuit either directly (when on high) or through the resister block when on a lower speed.

 

OK, yesterday I got down and wiggled the wires going to the fan, nothing happened, then I thumped the bottom of the fan with the heel of my hand and it came on, but now there is no defrost, just vent and floor. Had to thump it again when I picked up DW from work. Will remove fan today when it warms up some to see if I can see anything loose inside.

 

Pulled the fan, and it is the problem, it won't start, but if I turned it, it would run. Popped off the cover and WD40d the heck out of the inside of the motor, runs now but makes a lot of noise, but I hope it lasts until I can get a new fan.

 

After WD40 last winter, the fan has worked fine. I'll not change it until it craps out again, I have the new fan in a box in my tool box and a trex driver in the glove box for that time

 

Well, after all this time, the fan is starting to squeek and vibrate again, so I guess that the WD40 fix has finally worn out. Guess it's time to put the new fan in.