CorbinWelter

I jut bought an A6 C5 and the ac recently stopping blowing super cold like it did. It is now just warm, not hot but not cold. Pretty much outside air temp of 70 here. I tried turning off the ac and I can see the compressor clutch still spinning constantly. Nothing I do will stop it. I also tried hooking up a recharge kit and the psi shows around 90 on the low pressure line with the compressor on still. Can anyone give me any ideas what might be wrong?

georgeb944

Pull the codes with VCDS and let us know what they are.

CorbinWelter

I don't have anything to pull the codes

georgeb944

Then, take it to a dealer or someone who has the right tool to diagnose your problem.

jcman

Just because you see the clutch spinning does not necessarily mean that the clutch is engaged so are you sure that your'e not seeing the pulley turning? That one always turns when the engine is running.

90 psi static pressure is about normal for a stopped compressor with 134a on a 70 degree day on the suction side "low side", Do Not and I repeat "DO NOT!" add any freon to the system until you can actually verify that the compressor is running.

Things you can do:
1)Check the fuses and relays.
2)If the compressor is running all rad fans will be on.
3)The discharge line will very hot going to the condenser coil and the accumulator and suction line will be cold to the touch if the compressor is running.

CorbinWelter

The clutch inside the pulley is spinning with the pulley.

Fuses and are all good
Rad fans are running
Did not check these lines, will do tomorrow

jcman

Good Corbin, report back.

CorbinWelter

All of the lines were ambient temp. I also noticed I turn off the ac system and turn back on the rpm will fluctuate like the compressor is turning on/off like normal.

SloopJohnB@mac.com

Go get an AC manifold with gauges so you can actually tell what's going on.
High low side pressure (90psi) with compressor running and no increased high side pressure indicates no refrigerant flow….but all of this diagnostics you can look up online as well as with the little instruction pamphlet that often comes with the manifold. The manifold should also have lines and gauges and the lines should have the proper R134A quick disconnects for the high and low side pressure ports.

But no drop in low side pressure with the compressor running is a concern…..


Here is link to diagnostics…

http://www.examiner.com/article/air-...ge-diagnostics
http://ecx.images-amazon.com/images/...sL._SX466_.jpg

jcman

If you know for a fact that the compressor is engaged then the low side should be in the range of 25 to 35 psi and cold by touch even with the gauge you have, no change in pressure with a turning compressor means no pumping, like SloopJohnB said that is a concern and probably means internally the valves or swash plate are shot.