Ye gentlemen of much worldly knowledge.... any of you familiar with VW AC systems?

I have a 2001 polo GTI 6n2 with climatronic.

The AC has not worked for about 10 years but I would like it to work. I had it re-gassed a while back but there was already gas in it and the problem was not resolved with fresh gas.

If I turn the AC on inside the car the engine revs pick up from idle which is to be expected but if I put a probe on the AC clutch wiring I do not get a signal. I would also expect the rad fan to come on slow with the AC compressor but it does not.


Trying to work out how "smart" the AC system is - what else is in the logic tree that could be preventing the AC clutch getting power? What other sensors are there in the loop? Are there solenoid valves in the refrigerant loop?


There is a fan control module under the front left headlight which seems to be part of the system - mainly to control the engine cooling fan. I have replaced this in the hope it might help - it did not. I also replaced the cooling fan as one of the coils in it had burned out.


Its an old car - I get that - but VW are lazy and a lot of the components don't seem to have changed much over the years. I do wish VW would provide wiring diagrams etc for the older stuff!

Any thoughts on the best process to debug this?



Edit to say - the only fault codes relate to the V71 stepper motor for the recirculation flap. Eveything else seems to be ok... shrug

[Edited on 28/4/24 by tegwin]

Can't help with your problem, but I have had numerous VW, Seat & Skoda's (both company cars and private) over the years.

The VW group are kings of spreading the tech/systems/modules across the brands and getting the highest value they can from them. As you mention they will wring every last bit out of the system before migrating to a new one. Wiring diagrams - difficult to find/get hold of without being a VW technician. Often the best way is to find a similar vehicle with a working system and work from that (maybe hard with the vehicle you have though).

Had a Y plate Seat Alhambra that (after a leak fixed) was king of ice cold A/C
Had an 04 plate Seat Leon (co. car for 90k miles) was king of ice cold A/C
Had a 57 plate VW Passat that was king of ice cold A/C
Have a 67 plate Skoda Kodiaq that unimpressive A/C