Hello , Air con -compressor or sensor.

[tedroadster]

Hi all

I am a new member and owner so be gentle ;)..

I have been reading and researching a problem on a lovely Mk 5 Gti I just bought.

It's a 2006 2.0 gti, 80k, Black with Monza 2's. It was pretty much my perfect spec, and I got it at a good price, knowing it had a few niggles. What I didn't count on was this problem.

I have spent literally hours trying to identify the best way to diagnose my problem, I would like to avoid a dealer / garage as far as I can as I am out of cash for few months!

The problem:

No AC.

The AC is not cold although if I look down in the engine bay the pulley for the comp does go round.

The system is charged with refrigerant

I know many have experienced these air comp failures, but also the pressure switch - which being much much cheaper I am hoping will be my problem .

Before I test anything are there specific operating temps for the AC ie will it operate in the cold weather we are having.

If the pressure switch has failed does the small fan still operate with AC on?

If it should - would a faulty fan stop the aircon?

What fuses protect the AC Comp, rad fans? I have seen so many conflicting forums - can anyone tell me for sure on a gti.

Any other suggestions are welcome.

Thanks in advance

[martin@gti.co.uk]

Scan it with VCDS and it might point you towards the problem... It sounds like it might be the sensor or just low refrigerant. If you will get a new sensor get the purple oring seal as well. You can reach it with crawfoot socket and ext. If you spot weld it so it doesnt drop and do it in 2min without removing the front end. Just cut the old seal off with fine screwdriver.

[tedroadster]

Thanks for that.

Sounds like I will have to get a garage to plug her in.

The fans seem to me to be a possible clue - I would love to know if the sensor does prevent it spooling up. Would be a start, rather than blindly replacing stuff.

Anyone know the answer to that? The system is exactly right pressure / full, so it's either big bucks compressor or the sensor I reckon.

[doylebros]

VCDS allows the component testing of the aircon system,so tell them to do that test!

You could find someone from here:-


http://www.mk5golfgti.co.uk/forum/index.php/topic,120.0.html

To help you - the sensor is favourite - this is worth a look for prices.

http://www.autoairconparts.co.uk/volkswagen-golf-mk5-Car-air-conditioning-compressors-pumps-aircon-radiators-and-more

[wilmott1980]

Check to see if the center bolt on the pulley spins with the pulley when the engine is running and the air con is on.
If it is not spinning then the clutch system on the compressor is goosed and you will need a new pump.

[tedroadster]

Thanks for the advice thus far> the update;

Hopefully at some point this will help others - so i will list my progress and plans.

I will try to get the car read by one of the members, however with it being Xmas i think that will have to wait til New Year.

So to summarise;

The Air Con (Climatic) does not get ice cold. I think there may be slight chilling going on but very very slight?

The small air-con fan does not run whilst the air con is on.

I have checked the refrigerant and it is spot on.

I have now checked the Lower fuse for the fans SA3, which is functional.

I have checked the interior fuse 40 which is functional as is fuse 4.

I have checked the compressor turns whilst engine running as does the bolt in the centre of the pulley ( this seems to be good news)

I have checked the multi-plug to the fans> two of the four terminals show power across them 13.2V - ( i have limited electrical knowledge, but this power remains even with the econ button in - not sure what this means)

I am unable to test the air-con pressure sensor, so only option will be a straight replace - after codes read.

I have driven in rain and damp and as soon as i turn the econ button on ie aircon off, with only me in car, it starts to mist up, turn the econ back on and it clears.

So i am wondering if the lack of the air-con fans means that although some 'purified' clean air gets through to the cabin and clears the windows, it is not enough to do that properly and not chilling the air. ??

My next move is to research the small air-con fan, I hear that the brushes get stuck, and you can recondition them quite easily..

Any other views or suggestions welcome..

I am in Grays if there is anyone with scanning ability nearby? Will check the list that has been kindly provided as well.

[martin@gti.co.uk]

Pop in to local garage and ask them to scan your HVAC , but it all points toward the aircon sensor. About 50£ with seal, as they are common to fail. Unless you are going to clear the faults, the aircon will not work. Keep up the good work and good luck

[tedroadster]

Thanks for that< i didn't realise that the code would need to be cleared if i changed the sensor.

That's a pain!

[Len405]

having problems myself and did a search and found this thread!

I need to check the compressor as said above.

But if its the sensor can I DIY?? Without the need for degassing??

Also I assume there is nothing else inside the car I need to do to operate the system just turn both controls to LO???

[akbarirfan]

Does it really need to be on LO though? If you set it at say 17 degrees and the temperature from outside the car causes it to be greater than 17 degrees inside the car, then it should regulate itself if using Auto and no Econ mode.

[white91]

Did you get this sorted?

[Flyingscotsman]

Thread from the dead resurrection?

Are you having problems with your A/C ?

[white91]

Struggling to diagnose unfortunately, maybe I should try your switch after all


Sent from my iPhone using Tapatalk

[Flyingscotsman]

It's worth a try & cheaper than a compressor. I bought the part planning to do it DIY but had car in to dealer for cambelt change & got a/c done by dealer. Could have saved £200 by doing it myself !