My A/C fan will run for a while then slow down, then speed up, then down ect.
finally it will just quit.
Sometimes it will run a while then when i shut the truck off, when i restart it the fan will not run.

After searching i found no clear cut answer, anybody else having this problem
or fixed this problem

Rick

 

On the 04.5 the fan gets + directly from the ignition switch.

The control on the dash completes the ground side, either directly on high, or through the resister block mounted next to the fan motor.

There have been several threads where the wiring/ignition switch under the clam shell cover on the steering shaft have been charred.

Anyway, I think I would pull the 3 screws and undo the wiring connector to take the fan out just to make sure it spins OK (a bit of resistance is normal) and make sure it runs when 12v is applied.

If that is OK, take the cover off by the ignition switch. It is a good idea to first remove both negative battery cables and let it sit a while, in order to disable the air bag. My bet is you will find burn marks around the ignition switch and maybe also related wires.

 

I replaced the ignition switch today, the original was burnt pretty bad, took the truck for a test drive and worked great for half a block then the fan slowed down again.
I went and ordered a new fan and resistor, i'll install them this week and see what happens.

Rick

 

You might also take a look at the recirc door. They've been known to break and fall down over the fan.

 

I piked up the fan and resistor today got it home and the fan was broken, so installed just the new resistor and ran the fan back to the store. to my suprise the old fan worked perfectly, this thing will blow some serious air now, worked fine for a 30 min ride.

The old resistor was dark and burnt looking and the casing material was cracked.

Looks like between the ignition switch and resistor fan is back to normal.

Rick

 

Good deal. Glad you got it fixed.

 

Rick glad you got it fixed.

I had the exact same problem you described in your first post. Sometimes if I popped it under the dash with my flashlight it would work a while, but eventually even that didn't help.

I bought a new A/C blower motor and replaced it.......now it works perfect.

..

 

My 06 A/C just quit.... does the 06 have this same resistor?

 

Class Action Lawsuit

 

There is a resistor on the 06. It's the rectangle shaped thing next to the fan motor above the passenger footwell.

The way the wiring is set up, though, even if the resistor was bad (or even disconnected) the fan would still run on the high setting.

If the fan is not running at all, I'd suspect the ignition switch and related wiring on the column, but you would also want to check the fan motor (just apply 12v across it's terminals).

 

Get a grip guy, be helpful or don't post. .02 from me....

 

Thanks for letting me vent, guy.
This fine piece of engineering has crapped out on me for the second time in 3 months. Thankfully it happens while I'm out on the road working and don't have the time to get it into the shop, this time I'm in vegas where it's 115 degrees, last time I was in LA, temp was only 100 and I was 1400 miles away from home, a nice 22 hour ride through the desert. Next week when I get thru in Montana, then Colorado, I get to drive home to central Texas without A/C again. Getting a grip is not my problem....I have a 3yr old 36000 dollar truck that has a 5 dollar A/C unit, and a 2 dollar front end. That is my problem. I will continue to try to plant the Class action Lawsuit "seed" when I see new A/C problem posts, and I would appreciate it if you would get on board!

 

Ditto !!

 

I agree. Driving through West Texas at 3:00 in the morning and it is still 104* outside doesn't sit to well with me either.

Obviously there is a problem with the A/C systems on these trucks with soo many people having trouble.

David