No AIR CON Chilling. Both Rad Fans never run. MK5 Golf 2005 55 plate.

[golf144]

No Air Con Chilling. (ECON not lite) (Never Worked since we had the car VW want to charge
£210 for just the diagnostics.

Large Fan never runs even when engine very hot.
Small Fan never comes on when Control knob max. left.

As everything is controlled by ECU how can I go about fixing it.
Voltage to Compressor is only approx 2 volts DC.
Compressor works with 12v across it briefly

Have replaced so far:-
Large Fan (fans control inside)
Air Con Pressure Sensor
Radiator Coolant Sensor
3 knob control unit.
Air Con Gas Replaced & Correct gas & oil replaced.
Cleaned & exercised all connectors on RH corner (looking from front)
Removed, cleaned earth connections.
Removed ECU plugs (no bent pins).

[phil miller]

have you had any fault code read done at any point?? because if it has a stored code even after replacing the fault componant it still wont work untill you erase the code, by the look of what you have replaced i think you will have fixed it but the code is still present so the ECU wont fire up the AC compressor

[dcds4]

anymore news on this, have the same probs and great difficulty diagnosing the problem

[golf144]

Hello "dcds4" yes I fixed mine myself. Local VW wanted £210 just for a diagnostics so this spurred me on.

Had already connected "Small Fan" with 12v & it ran OK.
As I was running out options, info on the web said to check resistance of this fan. It was approx 35 ohms.
Took fan apart & one brush sticking in it's holder, also cleaned com. with petrol, refitted & BINGO. Resistance now 2.5 ohms.

(info for LARGE FAN, when using ohmmeter, between all 4 pins HIGH resistance)

Air Con now working first time since we had the car.
Now alls well with the world.

[dcds4]

Hello "dcds4" yes I fixed mine myself. Local VW wanted £210 just for a diagnostics so this spurred me on.

Had already connected "Small Fan" with 12v & it ran OK.
As I was running out options, info on the web said to check resistance of this fan. It was approx 35 ohms.
Took fan apart & one brush sticking in it's holder, also cleaned com. with petrol, refitted & BINGO. Resistance now 2.5 ohms.

(info for LARGE FAN, when using ohmmeter, between all 4 pins HIGH resistance)

Air Con now working first time since we had the car.
Now alls well with the world.

Thanks, will defo give this another look this weekend, my fans dont run and the compressor doesnt make any noticable click like my other cars used to when the ac is switched on. I did measure voltage at the compressor and there was 12v but then 10v when i turned up the heat..

[golf144]

What u can try is this disconnect plug to compressor, run engine & apply 12v (0.8amps) to compressor. Check that large pipe is getting cold.

CAUTION only connect compressor for no more than 10 secs.

Also you will not here a "CLICK" 'cause these compressors have a variable clutch

If compressor does not cool it might have seized and if so has "Fracture" system built in.

Check make, use a mirror as plate is on front of compressor. Best are "Sanden"

All the best.