tarpeyphoto

My fan stopped blowing a few days ago. I have looked around on the forums, and talked to a few people, and found that it is probably the blower motor. But possibly the relay or switch?

I have checked the fuse, and it is still good.

I have found threads talking about replacing the blower motor, but nothing really about the relay or switch. Just trying to figure out where they are, so I can test them.

Thanks for any help!

dorsal900

Auto Climate Control (ACC) setup does not use a "switch" or a relay to control the fan; instead, it is controlled by a large transistor that is controlled by the ACC head unit.

To test the motor, put the ACC controls in a position where it should be blowing. Measure voltage between the two wires that attach to the blower motor: if there is voltage (i.e. ~5 - 12V) there and the fan isn't blowing, it's dead.

a6fletch

I just went through this my self and have fixed the problem. Mine at least. This was all very easy to DIY. The heat and A/C were not working at all. I could hear the A/C compressor turn on as well as see the idle RPMs adjust as it kicked on. So I knew that the compressor was not the problem. If you have the Solar power sunroof (hot weather package), I'll bet your problem is the same as mine. It was the Solar relay switch. (Called around to two Audi dealers in town and they both had it listed under different names, "Solar relay switch" and "sunroof control module". $70. Took off the under dash on the driver side. Five screws i think and had to pop off the little part above the steering wheel. Pulled out a Fuse like box that was clearly marked 385 in big white numbers. This is what you want to replace. Really easy and cheap. If you email me. i'll send photos.

TwoPointSevenTwin

Thanks Man, this also worked for me, I have the Solar roof too. quick and easy fix, Hoffman Audi in CT wanted 125$ for the relay got it from ecs tuning for 75$

tommyd291

Can you send me pics of how to do that? To Heanto@aol.com

tommyd291

Can you please send me pics on how to do that?/? To heanto@aol.com

yongbuck78

i have the same problem but my ac control blinks for about 2 min every time i turn the ac or heat on is that normal

kgabri

This same thing just happened to me. The fan just stopped blowing air and i can hear the AC compressor kick in. How do i tell if i have the solar roof?? It would be awesome if i could figure this out on my own.

Thanks!!

a6fletch

Look on top of your car and if the sunroof looks like a solar panel- then replace the switch.

AudiMick

Solar sunroof is a fairly rare option on the A4, so all of you chiming in thinking this is going to be your solution are probably SOL.

It was I believe a MY 2000/2001 only and mostly on "high end" V6s if memory serves me.

Like dorsal900 said it's usually the blower that either burns out or the bearing dries up and it won't turn. Replacing it is pretty easy and not typically that expensive.

Note: The AC/ heat blower is the one inside the cabin behind the glove box, the AC fan is the two speed electric cooling fan behind the condenser/ radiator at the front of the car.

If you confuse the two be prepared for some grief when trying to diagnose the problem.