Air Con and or Fan fault, help please

[tt ted]

Hi everyone


I am looking for some real help here. I am a bit skint and trying to fix my non functioning aircon on my 2006 Mk 5 Golf GTI


I know our cars suffer from problems with the air con compressors, and I have spent literally hours reading about these problems.


The symptoms;
When climatronic AC is on, no cold air
When AC is on, Neither fans work
If I drive at 60+ and have the AC on it feels like it is working, I am guessing because the air is chilling the Freon.
Whilst engine running the compressor is turning and I am told that if the pulley looks like it is turning then that is a good sign?


I have::
Checked the fuses, both boxes.
Removed the fans and bench tested them, both work.
Checked the gas, full to right level
Replaced the air con pressure sensor, (as got it on big discount from shop)
Removed fuse 24 (in engine bay) with engine running and apart from throwing a few warning lights this turns on both fans full pelt???
Checked fuse SA3 in engine bay, and the contacts
I don’t have vagcom or similar or know anyone that does.
Questions
Is there a fan control module that I should check
Any method of checking that the aircon is calling for the fans? I.e. what contacts are what in the fan multi-plug?
Any help will be greatly appreciated, this will / maybe serve to help someone after me.

Thanks in advance

[Flash2]

Hi there.
Can't really help you much with your aircon fault, but I can tell you that the fan controller is built into the larger of the two fans.
The fans are controlled by the engine ECM. If you look at the fan connector, you will see the main supply and earth (the heavy wires) and two thinner wires.
The thin green wire is a digital data bus wire linking the fan and engine ECMs. If you had vagcom or similar you could check to see if the engine ECM was sending a signal to activate the fans.
You could also use vagcom to manually command the fans on. Because it uses a digital signal, there is no other way to check it that I can think of.

You will really have to have your ECMs checked for trouble codes, both engine and aicron.
Perhaps there is a wiring fault between the gas pressure sensor and the aircon ECM. Although there is gas pressure in the pipes, the ECM may not be seeing it and so wont start the compressor.
Perhaps there is a fault in the engine ECM that is stopping the fans from working?

I'm not sure if this effects the operation of the aircon, but there is a tech bulletin from VW about the fans failing due to dirt getting into the smaller fan.
This results in a DTC being logged in the engine ECM but as it's not emissions related, it may not cause the engine check light to come on.
Sorry, I can't remember the DTC off the top of my head, but having the fault memories checked would definitely be my next step.

Regards.
Jim.