Air Con not working - advice please!

[jaaaames]

Hi there,

Hoping that someone on here can help me

The air con wasn't working at all. So today I had the air con on my '04 audi a4 b6 1.9 tdi regassed.
I was told that the system was completely empty before - it's full now and correct pressure. I've only had the car about 4 weeks myself so don't know how long it has been empty for before that.
So the econ light on the cc unit wouldn't turn off before (i assume because the system was empty) ...I can turn it off now.
But the temp from the blowers when I have it on the lowest (with econ switched off) is still about luke warm at best. Definitely not cold. It's colder with econ switched on...which from my understanding should turn the air con off!!
Checked the fuses by steering wheel...all good there!
So full air con system still not working.
Any help or advice would be much appreciated!!!

Thank you!

 

[Laurie P]

I had this problem with mine when I got it, same issue - was the compressor. Wasn't cheap as I recall a couple of hundred quid.

 

[jaaaames]

Ah I hope not! I was hoping it would be something easier and cheaper. Is there anything I could check out before forking out a couple of hundred quid?

 

[Mac76]

Ive got the same problem I'm trying to sort at the moment
I have checked the voltage going to the compressor on mine its only 9.4 V so it looks like i have a problem with the wiring some where
If i manage to sort it ill post back

 

[pauldazzle]

A/C Pressure switch is a common failure.

 

[vr6gordy]

If it was empty you must have a hole somewhere .. Didn't they put a dye in the gas when they refilled it to see if there's a leak anywhere.

 

[jaaaames]

Yeah they put a dye in it. And pre tested it (not sure how) to make sure that the would hold the gas. I've been told that the compression remained stable and the system should not have any leaks and to just run it over the next couple of days to see if the little lubricant that is in the air con gas might "unstick" anything that might have sealed up......I'm not optimistic that this will happen though.

 

[s4mark]

Had this issue on my s4, went into safe mode with econ light constantly on. Had it regassed but 3 weeks later done the same. Changed the pressure switch but didn't help. Ended up getting a second hand compressor and has solved the problem touchwood

 

[jaaaames]

I'm gonna look into the pressure switch. Worth a go! What are compressors like to change?

 

[s4mark]

I'm gonna look into the pressure switch. Worth a go! What are compressors like to change?

Not sure about yours but my s4 one was a pita so had my specialist do it. Very fiddly on the v8 apparently

 

[hodgy0_2]

Tried my air con today and nothing (2.5 Quattro)

Weirdly the Econ light stays off (and even more weirdly does seem cooler with the light ON) - which on the face of it indicated the compressor was engaging, so my working hypothesis as I was driving home was very very low pressure, enough to engage the compressor but not enough to produce "cool"

Anyway when I got home I looked under the bonnet - and the compressor belt is missing, it looks like the tensioner disintegrated

So will replace the belt and tensioner

I replaced the pressure switch a year or two ago, that cured the compressor not engaging, and the light staying on Econ

 

[jaaaames]

Tried my air con today and nothing (2.5 Quattro)

Weirdly the Econ light stays off (and even more weirdly does seem cooler with the light ON) - which on the face of it indicated the compressor was engaging, so my working hypothesis as I was driving home was very very low pressure, enough to engage the compressor but not enough to produce "cool"

This is exactly what I am experiencing...feels cooler with light on...which should be wrong!! Apart from mine should be at the correct pressure as i just had it regassed.

 

[jaaaames]

A/C Pressure switch is a common failure.

http://www.eurocarparts.com/ecp/c/A...87a50b23695a87f1bdbea602bf5884548c63a5&000526

Is this right?

 

[leigh72]

Had a similar issue with my 02 1.9 tdi air con not working. Turned out to be the clutch housing of the front of the air compressor pulley had come loose, found it on the engine under tray. Bolted back on with some loctite and hey presto back to normal.

 

[hodgy0_2]

This is exactly what I am experiencing...feels cooler with light on...which should be wrong!! Apart from mine should be at the correct pressure as i just had it regassed.

I suspect that maybe the incoming air goes through a different route - the Econ switch seems to alter some internal flaps

But could be wrong

You need to check whether the compressor is engaging when the Econ light is turned of - if not then it is probably the switch

 

[hodgy0_2]

http://www.eurocarparts.com/ecp/c/A...87a50b23695a87f1bdbea602bf5884548c63a5&000526

Is this right?

Looks right, although I initially bought one that looked right was not an exact match

My car, on a 52 plate seems to be a crossover model - in that sometimes parts are very slightly different from normal

I had this gently with a driveshaft, all the ones listed as fitting it (GSF, Eurocar part etc) were slightly different

It had to be ordered via the chassis number

 

[Mike.M]

The main problem with Air Con is that most people only use it in the summer, but it needs to be used all year round to keep all the seals luricated so they do not dry out and shrink and cause problem further down the line.

Mine is never turned off and works perfectly..........needs a regass this year as it should be done every two years

 

[abyrne153]

You can check if the aircon is operating by running the car for a few minutes and then checking the pipes close to the air box. If the thicker pipe is stone cold and the smaller pipe is slightly warm then the system is working and most likely a flap motor is causing your problem. There is also a plastic gauze in the pipe next to the filler nozzle which can block and cause the the smaller pipe to run colder which is wrong and will effectively cause the system to generate heat rather than cold. This cone shaped gauze can only be replaced when the system is degassed. Check also that the clutch on the pulley does not spin freely when the engine is off. You should not be able to turn the plastic cover by hand, if you can then the clutch in the compressor pump is faulty.

 

[Greeny233]

Check the pulley on the compressor it should have a plastic cover over it which hides a rubber "cush" drive. My aircon stopped working on my old A4. I had it re-gassed and it made no difference. When I looked at the pulley it looked ok but I was told they fail quite often so I ordered a new one and it wasn't until I got the new one I realised how much was missing from the old one. Fitted the new pulley and hey presto the aircon worked a treat.

This is what the pulley looks like disassembled. All that was left of mine was just the pulley.

Sent from my iPhone using Tapatalk

 

[hodgy0_2]

Ok - replaced my belt and tensioner pulley just now - just look at the state of the old one

I think it has done the job - difficult to tell because it is fvcking cold anyway - but the fat pipe is cold and the air on "low" is pretty cold too

 

[jaaaames]

You can check if the aircon is operating by running the car for a few minutes and then checking the pipes close to the air box. If the thicker pipe is stone cold and the smaller pipe is slightly warm then the system is working and most likely a flap motor is causing your problem. There is also a plastic gauze in the pipe next to the filler nozzle which can block and cause the the smaller pipe to run colder which is wrong and will effectively cause the system to generate heat rather than cold. This cone shaped gauze can only be replaced when the system is degassed. Check also that the clutch on the pulley does not spin freely when the engine is off. You should not be able to turn the plastic cover by hand, if you can then the clutch in the compressor pump is faulty.

This is really helpful!! Thanks for posting that will check all those bits when I finally get a chance to!

 

[jaaaames]

Ok - replaced my belt and tensioner pulley just now - just look at the state of the old one

I think it has done the job - difficult to tell because it is fvcking cold anyway - but the fat pipe is cold and the air on "low" is pretty cold too
View attachment 88895 View attachment 88896

Are those 2 supposed to be the same part!?

 

[hodgy0_2]

Are those 2 supposed to be the same part!?

lol, yes - the one on the right is simply the "middle" bit of the one on the left

it actually comes with a plastic cover that clips on to protect it from all the road grit

and it has definitely fixed my issue

it is amazing the state it was in tbh as the car gets used pretty much everyday