Air Con Problem?

[nevo]

The shaft turns regardless whether it's on or off. The centre bolt is tight.

Looks like you have no clutch then, you will need vcds to see what codes you have.

[karlkane]

Well I brought back the original and got a replacement fan and fan control module - guess what, still the same. I run a scan whilst driving and logged coolant temperature and it climbed as normal so temp sender unit is ok. I checked the output of the FCM, the smaller of the two pins and one side reads 12v, the other goes from 2.5v to around 0.5v, in 5 second pulses. im thinking it maybe a ground connection somewhere but buggered if I can find it. Does anyone have electrical diagrams for these? I am cracking up here lol
Karl

[rowdy-999]

An little update on mine. I got OBDeleven to scan for codes (great little piece of kit I think), and did the scan on the way to see a a/c specialist. It threw a pressure sensor fault code which I thought was odd with a new sensor. After a bit more digging I may have fitted the wrong one (even though I double checked the part number etc). Specialist checked the system which had gas in, and for the short space of time it was running gave normal readings. So I've ordered a different sensor, and will take it from there. The specialist was very knowledgeable and didn't charge me a thing ....I can PM his details for those in the Staffs area if required.
On a side note the scan also threw a fan control module fault.....although one fan does kick in with the a/c. I believe both should.

[karlkane]

Developments so far - After trawling through the web and having my head under the bonnet I have come to a couple of conclusions.
1) On single fan systems such as mine the fan comes on when in ECON mode only when necessary ie. like a normal fan. The speed in which it turns is determined by the pulse width modulated signal provided by the ecu.
2) When ECON is of, the fan comes on and stays on.
3) I am getting 7-8v at the compressor when the air con switch it put on - when its off it reads 0v. I was surprised to see only 7-8v as I was expecting 12. Having read a number of posts it seems to vary but I cannot say with any certainty if this is correct. However I can see the voltage change from 0v to 8/9v when switched off and on. So it seems as if the electrical end of thing is ok. If there is another reason why I would be getting voltage at the compressor but it not coming on please advise. Cant see it though.
4) The ohmic value of the coil is 11 ohms. Not sure if this is normal, if anyone can advise please do.
The clutch plate at front has not loosened and centre screw is in place. I don't know if it is turning the compressor though.
5) It does not seem to be the fan control module. I have another bought from a scrap yard (second one I got) and its the same.

If anyone has any additional info please let me know when you can.
Karl

[Rob69]

If you can get under the car front end you should be able to feel the compressor kicking in, if there is no change in engine note and you cant feel anything, then it sounds like the clutch is not pulling in or compressor internals are shot, seized and sheared shaft possibly.