AirCon regassed, no leaks, no fan??

[necroeire]

I already posted this in the AirCon section but that doesn't have too much traffic these days so I'll post here too as I'm hoping of rsome drawing or help identifying parts.

2001 B6 A4 1.9TDi

No matter what temperature I set it to it will only go to ambient, and since I've only used it in the last few days for the first time since last year the aircon has stopped working.

Yesterday I brought it to an AirCon service centre for a regas and the guy done a pressure test, it was a little down but not by much so he pulled a vacuum for 20 minutes then injected die and filled it up to I think it was 520g of coolant.

His test rig indicated all was fine. However I did notice while there that when the enginer was running and I pressed the Auto button the fan on the left side of the radiator as I looked down on them didn't start. I asked the service guy if he could monitor the pressures as I switched from ECON to AUTO to see if the compressor was coming on or not. Seems the pressure stayed the same through out. I was not able to hear any distinctive click when I switched from ECON to AUTO either. I have seen in some other posts that the fan will not swich on until after the compressor.

So some of you may remember the crash I had over a year ago where I hit a pole and had a front end of the car rebuilt, well I can't remember if I used the AriCon since then with our wonderful weather, so I'm wondering if it may be an electrical fault or a bad connection on the compressor, or worst case a f**ked up compressor.

I checked all the fuses and they are fine, so now can someone direct me to first identify the compressor in the engine bay and second where the wiring is on it for the AUTO to start it running? Any pictures would of course be even more helpful.

 

[NHN]

Any vagcom readings done to see if any faults reported from the climate unit, does it stay on econ aswell & doesnt even switch to auto when pressed?

 

[necroeire]

Checked VagCom and there were no errors showing up. It looks like ECON and AUTO switching is fine however there is just heat out of the AirCon. When I switch from ECON to AUTO the air goes to full speed and when I slow them down in manual and select AUTO again they back to full speed.

 

[Xmay4444]

When you select the auto button, the A/C will try to cool the car down as quickly as possible by wacking up the fan speed. When it gets to the preset temp, or near to it, the fan speed will settle down to about 2 or 3.
The moment you touch the fan speed or the airflow buttons, that switches off the auto mode.

 

[ScottyP45]

the pump is attached to the engine mate, just follow the silver AC pipes that go thru the bulkhead, on the drivers side near the air filter and passenger side above the firewall but under the plastic cover, they lead to the pump. The belt could be broken so its not getting driven, or the plug may have come out of the pump that controls its clutch etc.

 

[Broken Byzan]

I would look at the compressor to see if the wires are connected, especially if the VAG scan showed nothing. I am still fighting mine to try and fix it, parts everywhere

 

[henry74]

I'm in the same boat and have been for over a year now! On the first hot day last summer when I got in the car to come home from work I turned the air-con on as usual and nothing happened. Took it to an indy air-con specialist who told me that I needed a new compressor at £400 + VAT fitted! As our baby was on the way the finances were shot to pieces so there was no way I could afford to get it done. However a work colleague had a voucher for 25% off an air-con check at Kwik-Fit so I let them have a look, 2nd-opinion-wise. They re-gassed the system but still nothing but they proved there were no leaks and because they didn't fix the problem their policy is no charge! Apparently there is a pressure switch on the system that can go faulty and when it does you get no air-con as the faulty switch prevents the compressor from kicking in. When I took the car to the local stealers to have the cam-belt done I asked them to run a diagnostics to confirm whether it was the switch or the compressor. Unfortunately when I picked up the car they'd 'forgotten' to do the check (at least I saved £100!!!). However they said that when I booked it in for the next service (yeah, right!) if I reminded them they would get a pressure switch in to stock to try it?!? The switches are ball-park £70 so I'm tempted to try that anyway - I just haven't gotten round to it yet! Hope this helps

Richard

 

[Broken Byzan]

There is a way to test the switch by temporarily bypassing it to make it activate the pump to see if it is the switch or not

 

[henry74]

Tell me more coz if it saves £70 then bring it on! Unfortunately I'm not sure of the actual location for the pressure switch (I'm sure I saw it in my brother-in-law's Haynes manual but now I have one of my own I can't seem to find it!) or how you go about bypassing the switch - do you just unplug and join a length of cable across the connections? All info gratefully received

Richard