AC Fault - AC Compressor Not Engaging - Help Please

[muddyfox470]

Hello!

Recently had the AC recharged in my Seat Ibiza (2003 1.9TDi Sport PD130 Engine) that cured the flashing of the climatronic, however it made me discover that the AC Compressor is not engaging or is broken full stop.

Garage which charged the gas said that it would cost 850euros to replace and fix
However I am wondering if there is an alternative to replacing the AC compressor and associated bits.

The compressor is a Denso 6Q0 820 803D (VAG code), so fortunately not a sanden one which tends to throw the clutch away.

I checked on the climatronic secret menu which reports between 4.8V and 5V at the compressor, so power is going to it, so I guess can't be a wiring or fuse fault.

I hand turned the compressor to check nothing had seized and it rotates as I would probably expect (i.e. not freely but with a little resistance as if it is turning something).

I don't have access to the VCDS as the windows laptop is currently with the GF, but prior to the service I didn't have any errors after getting a few things fixed, which included sorting out a few broken wires/earths which were discovered during a service.

The clutch obviously doesn't engage and the AC won't work, is there anyway I can force it to engage or to route out any alternatives before believing I need to spend so much money?
I can live without AC but I would prefer it if I didn't.

Thanks for whatever help you can offer!

 

[muddyfox470]

I just looked through the past fault codes on the system, before I cleared them.

Had F129 AC Switch Error, so do you believe that would stop the clutch from engaging?

Thank you!

 

[PLuKE]

Mine did th same.

The clutch on the pully can wear out, which in turn stops it kicking in.

If you look at the bottom of the pully there is a black wheel with a bolt in the middle, if it turns it's buggered, if you take it off and remove the washer I the middle it will work again. There is a thread on here a few pages away explaining I think.

Luke

 

[muddyfox470]

Luke, thanks for the reply!

I've managed to look into a few other forums that state the same (as what you suggested), reducing the shim depth to bring the plates back closer together...

Is this the thread you're on about: seatcupra.net/forums/showthread.php?t=195916 ? [can't post full urls yet]

I take it with the position of the ac compressor going from underneath the car is best? Now to buy a pair of ramps, don't trust just a trolley jack...

These were the results that pointed to a pressure switch - but since it has been regassed I haven't re-run VAG-COM but after I cleared the error when I bought the car it didn't show up again...

Address 08: Auto HVAC
Controller: 6L0 820 043
Component: CLIMAtronic PQ24 0201
Coding: 0000000
Shop #: WSC 00000
1 Fault Found:
00792 - A/C Pressure Switch (F129)
000 - -

 

[attila_tdi]

sorry to bring up an old thread but was this problem ever sorted out?

My AC is not working - been told by the garage its compressor but I am not getting any fault codes on VCDS?! I am getting this error:

Defroster Flap Positioning Motor (V107)

But I can't imagine this would not let the compressor engage?

 

[attila_tdi]

I've just been trying out the secret diagnostics on the climate control display.

Does anyone have a list of what the functions mean? i only get 51 options.

 

[RUM4MO]

The defrost flap motor being faulty would not stop the compressor running. These compressors do not have a proper clutch to engage/disengage the drive, they are running continuously but when not required, run at a very low duty cycle - effectively a variable dsiplacement compressor. What it does have is a form of shear coupling to disengage the drive pulley from the compressor shaft - just in case of failure as this saves stalling and/or breaking/throwing the ancilliaries belt. Shear coupling is a series of rivets I think, though it seems with heavy use, the keyed part at the end of the shaft/pulley can also give in.

 

[attila_tdi]

Thanks Rumamo that's very helpful. I'm nearly loosing my marbles over this. It looks like no one on the internet has ever changed a compressor on one of these before!

When the engine was running I noticed the centre part of the compressor did not spin. Additionally when I switched it off the centre piece was quite easy to spin around. Do you think it could be the compressor that's gone?

I have also done the climatronic test and noticed 4.9V constant going to the compressor however it did not change if I switched ac on or off.

 

[RUM4MO]

It seems that I was wrong when I said that the shear coupling is a series of rivets, elsewhere I've read that it is now a rubber/plastic combination - either way its a shear coupling to protect the auxiliary belt etc. I've also read that you can remove a shim from behind the pulley so that the pulley will get moved in and so regain a bit a "grip". Exactly how long this fix will last would remain to be seen, and yes, if any part of the drive pulley is not turning then the compressor will not be getting driven. Remember most of these facts are gleaned from forums and not from personal experience!

 

[J44APX]

I've just been trying out the secret diagnostics on the climate control display.

Does anyone have a list of what the functions mean? i only get 51 options.

How do you do this on the Ibiza anybody ?
Ive looked on YouTube but can only find a demo on the Audi TT

Any info would be great

 

[attila_tdi]

Try this:

http://www.nanoprotec.it/tips_and_tricks/codici-di-errore-del-climatronic-seat/?lang=en

Also press bottom flaps, middle flaps and econ buttons all 3 at the same time. Scroll through the options using the temp dial. Press econ to get out of it.

 

[bagshot]

I had the compressor not turning fault on mine, the pulley has no clutch on it like normal aircon compressors and runs all the time with a valve in the rear of the compressor controlling the output, the pulley has a rubber drive in it thats designed to shear if the compressor stops for any reason while running to prevent the belt breaking, now I suspect over time this rubber drive could wear/weaken and shear. I tried to sourcing a new pulley but couldn't find one which ment new compressor at around £300+ so I simply locked the pulley back together with 2 short screws through holes already in the pulley, these lock against the rubber in the pulley and allow it to all work again, now this is a bodge and could well cause the belt to break if the compressor stopped but I think the screws will just shread the rubber if that happened but couldn't say for sure. I've run mine like this for several months now and its been fine so far, so may help someone else.

 

[vroomtshh]

I've got a spare air con compressor

 

[attila_tdi]

I had the compressor not turning fault on mine, the pulley has no clutch on it like normal aircon compressors and runs all the time with a valve in the rear of the compressor controlling the output, the pulley has a rubber drive in it thats designed to shear if the compressor stops for any reason while running to prevent the belt breaking, now I suspect over time this rubber drive could wear/weaken and shear. I tried to sourcing a new pulley but couldn't find one which ment new compressor at around £300+ so I simply locked the pulley back together with 2 short screws through holes already in the pulley, these lock against the rubber in the pulley and allow it to all work again, now this is a bodge and could well cause the belt to break if the compressor stopped but I think the screws will just shread the rubber if that happened but couldn't say for sure. I've run mine like this for several months now and its been fine so far, so may help someone else.

anyone else tried this quick fix with success?

 

[ndanika]

anyone else tried this quick fix with success?

I would be intrested too, also, does anyone know how difficult it is to change the actual compressor?

 

[attila_tdi]

sounds like no one has been able to do the compressor fix.

 

[Priezti]

Where is the pressure switch guys?

 

[speedfreak123]

Where is the pressure switch guys?

On the high pressure line (thin pipe)

 

[Priezti]

On the high pressure line (thin pipe)

I meant location wise I've found it, near and below the coolant header tank

 

[darkhorse]

anyone else tried this quick fix with success?

Yes but only for testing purposes, it's a bodge and could cause problems. Once tested, I then got a complete compressor from a breakers and just swapped the pulley over. Total cost was £60 and I still have a compressor as a spare