AC acting weird.

2006 Jetta TDI. My sons car. He says the AC will run and seems ok. Then when he stops at a light and it idles for that amount of time, the AC quits working due to the fans stopping. He came over and we found that his large cooling fan was not working. I had a set of fans from another TDI I am working on that tested good. So we put them on his car while we waited for new fans to come. The fans came and were put in the car. Didnt hear from him for a week or so until yesterday, when he said the fans do not always run and he can tell obviously because the AC stops. I am trying to get his car to see what more can be done, so I thought I would post here and see if anyone can point me in the right direction.

I have not checked pressure as of yet, but will do when I get the car. Still trying to figure out the AC process with my gauges so any pointers will be good.

Oh, I also mention that in the mornings when he drives to work, they do not have a problem. It is when he is coming home when its around 100 degrees that they stop working,

Is there a fan relay similar to the MK4 Jettas that could be an issue?

Thanks

Probably a bad RCV.

In addition to the extensive treatment of the A/C issues in this forum, there are a couple of useful youtube videos that explain the systems and their likely failure points somewhat.

https://www.youtube.com/watch?v=xMrU4XimsoI
https://www.youtube.com/watch?v=pDQOvava64w

The Sanden compressors are called swash plate or wobble plate compressors, and the most common failure point is fouling of the refrigerant control valve (RCV), which is either held in place with a single bolt or a circlip.

kdawg89 said:

Probably a bad RCV.

Click to expand...

i replaced mine and charged at proper level and seems to make a big difference.

Traded cars with my son so I could get into this. I do have VCDS, so hooked it up to check and found a code in the HVAC module for the High pressure switch. Just so happened that I had one of them. Swapped it and then drove the car into work this morning. No issues with it turning off. Lets see how it does on the way home when the temps are a little higher. Will post again later.

The AC is still doing fine.