I was driving home from work the other day and my A/C started blowing warm air. No noises, no grinding, no change in performance or feel of the car.

I haven't checked the fuse yet, because if I'm not mistaken, the blower wouldn't work either if that fuse blew. But I could be wrong.

I thought it may have been a refrigerant leak causing the compressor to shut off. So, I had a can of R134a with a gauge on it, so I hooked it up to the low side valve and the pressure needle went all the way up into the "Red Zone". According to the instructions on the bottle, this means there's some other issue with the system.

I've had the entire system replaced by Audi a few months after warranty expired a couple years back. (they paid for parts, I paid for labor)

Any ideas/suggestions on things I could try/check on my own before bringing it in to a stealership?

Also, anyone know of a good Audi repair shop in South Jersey?

 

I am going through same problem with 01 TTR; There is an electrical hi/low a/c pressure switch located under hood,passenger side, on high side refrigerant line. This switch turns off the a/c compressor if R-134a pressure is too high or low. Hope this helps.

also, the blower will still run normal,only the compressor shuts down. Speaking of stealership, Audi wants 180.00 for part but you can cross reference with VW Passat 1.8 turbo for same exact part...86.00. Even less online.

 

Thanks!! I'll let you know how it goes

 

My 03 is blowing hot also, trying to figure out if its something simple or not.

 

I have been fighting with this for a couple weeks now on my 01 ttq. I replaced the pressure sensor and nothing changed. The compressor still does not come on and it just blows warm air. I really need to get this fixed because it has been over 100 for weeks now and I can't afford to have a shop do it. Any ideas?

 

I feel your pain... was able to replace my defective a/c pressure switch but had to have small German car shop use scanner/software to clear error codes in Audi computer for a/c compressor to engage.
So, we have cold air now, only about 15 electrical issues left.

If this helps,(Inimical) the tech told me there are 3 different sensors that are in the Climate Control section of computer, or, worst case, your compressor went South.

Of course he only fixed that 1 computer /sensor code for the air. Will have to "come back" to reset all other codes that appear from the endless computer /sensor loop.
There should be a computer that tells you how much money you toss due to the computer maintenance required.

My next step is to purchase scanner to do own diagnostics and repairs within the limits of my mechanical expertise. Is Ross-Tech the only way to go? I would like to have a scanner that can do all my work related vehicles.

This forum has been an excellent source for problem solving tech issues. I will be happy to share after I confirm and validate what the hell I am getting into.
Thanks, TTRIDER.

 

I ordered the new switch and that should be in this week. Did you have to empty your refrigerant to replace the a/c compressor switch on the a/c line?

 

check the fuses under the cover directly on top of the battery

 

Hi Guys,

Resurrecting this old thread as I have the same issue.

I've ordered a new switch from Amazon Prime - $39.00 with next day delivery.

My ac was working fine on Sunday. I stopped for gas and when I left the gas station the ac was no longer blowing cold. Hoping it's the pressure switch.

My question is:

Will I lose refrigerant when I change the pressure switch? Want to buy refrigerant today if I will need to top it up.

Thanks!
Russ

 

July 5, 2018

Quick followup:

I went over to the UK audi forums and found them very active on early Audi TT's.

1. Replacing the pressure switch will NOT empty the R134a refrigerant.
2. My problem was the left most 30a fuse in the battery top fuse box. No need to do anything to the refrigerant or other parts. I got lucky!

Here's the thread on the UK site:

https://www.ttforum.co.uk/forum/view...11939#p9011939

Hope someone else finds this useful.

Russ