OK so it's not a Skoda but one of my neighbours has a 2002 VW Golf TDi. The A/C was working fine, but suddenly packed up. He's had it re-gassed but still no joy.

I've looked at it as there's no feed to the compressor. If I supply a feed to the compressor the system works perfectly well, which suggests it's not a loss of refridgerant. The cooling fans do not switch on when the A/C switch is operated. The compressor wiring goes back to a multi-function relay beside the radiator. A live feed from the A/C switch is present at the relay, and the compressor will work if the relay is bridged. The relay itself has been replaced, and would seem is not the problem. The cooling fans will work if the fan switch is bridged.

From here I need a more in-depth knowledge of this particular system or a wiring diagram. The A/C will only work if the outside temperature is above 5°C, and if there's a minimum pressure in the system. There must be sensors that will prevent the relay from switching on if the criteria isn't met. The engine also has to be running and so the engine ECM presumably switches the relay.

My attention now turns to the inside of the car around the evaporator area, and because the dash is a pig to remove on these I don't want to remove it unecessarily.

Any ideas would be gratefully received......

It could still maybe be low pressure- have that checked, and then check the pressure switch. It won't let the compressor start if that switch is telling it there's not enough gas.

You might want to hook up VAG-COM and see if there's a stored fault.

It could still maybe be low pressure- have that checked, and then check the pressure switch. It won't let the compressor start if that switch is telling it there's not enough gas.

You might want to hook up VAG-COM and see if there's a stored fault.

I did remove the plug off the pressure switch and bridge it. There are three terminals on the plug which is fitted right on the bulkhead behind the inlet manifold. Nothing I did made any difference. It's very difficult to access the switch and plug in situ so I couldn't check it properly with my multi-meter.

I do have VCDS but only the Climatronic system can be checked with it. Manual air conditioning cannot. I do have one lead though, when the engine control module is open and I'm carrying out an output test, one of those tests is to switch on the A/C compressor. Well that doesn't work either, so I suspect that either there is something that isn't switching the relay on or there is a lost feed or earth somewhere. The pressure switch and temperature sensor may be earth side of the relay and earthed by the ECM. It is of course possible that the ECM is faulty, although I doubt that and no fault codes are present in any case.......