Ac clutch relay in touran

[masterinengland]

Hi there. I am having issues on my touran 2004 1.9 tdi. AC doesnt seem to work. AC clutch not engaging. I have read forums and mentioned it could be fuse or relay. Where can I find the ac clutch relay?

[Crasher]

The Touran uses a constant drive compressor where the amount of work done is controlled internally by a modulating valve and the compressor pulley drives continuously so it does not have a magnetic clutch, relay or fuse. IF the compressor should seize the outer section of the pulley breaks away from the inner and keeps spinning and you have to look quite closely to see this. The valve on the compressor is called the "N280 Air conditioner compressor regulating valve" and this is driven by a signal down a single wire (initially green but then changes to white/red) from the "J301 Air conditioning system control unit" but, and I quote the VAG manual, "The air conditioner compressor regulating valve -N280- is an integral part of the compressor and cannot be replaced as a separate item". The testing procedure is to read the fault memory of the HVAC system to see if there are any relevant codes such as the N280 being open/short circuit or indeed a pressure fault as the pressure switch is prone to leaking. If there are no relevant codes and the pressure is correct you are supposed to use a very expensive piece of equipment to check the current consumption but in practical terms we look at it as "no codes, no cold air, new compressor"

[masterinengland]

Hi mate. That was a thorough explanation. Glad you find time. I have my friend interrogated it with a vagcom and there wasnt any fault code detected. Is changing a compressor a huge job? Practically speaking is it worth just buying used one instead of brand new? Cheers.

[Crasher]

I won't fit used, just don't trust them and you can get a top quality original Denso for £420, from VW they are £545.60 exchnage. Be very wary of these £300 eBay units as they are often awful quality Chinese copies that are made from rice and noodles. It is essential that the system is completely clean so if you find your compressor has seized, the system may be contaminated with metal fragments and unless they are COMPLETELY flushed out they can destroy your new compressor in seconds and it will not be covered under the manufacturers warranty, and this does happen, I have seen it. Yes changing it yourself is practical but you will have to get someone to come discharge the system and then later return to vac out and re-gas the system PLUS it is a criminal offence to knowingly discharge AC gases into the atmosphere.

[masterinengland]

That was excellent advice. I shall start searching for one. Many thanks for your time and sharing your expertise. Appreciate it loads matey.