A/C problems, I'm lost.

Craig hopkins

Registered User
Hi all,

I've never been able to get my A/C to work on my 2002 1.9tdi AWX, first time it was due to the high pressure sensor being bad which I replaced but it had been emptied of refrigerant so couldn't test it.

Had it filled up the other day and econ light now stays off (no high pressure sensor code showing either so that is working.)

However, even with econ light staying off and it being filled it still wouldn't work, checked the A/C compressor and found the clutch was missing, got a second hand one, screwed it on and it all spins nicely when engine on (spins with econ on or off and does not spin freely when engine off).

I am now getting signs that it is trying, you can hear the gasses through the metal pipes next to air filter, thicker pipe goes slightly warm and thinner one feels cold, same thing next to the pollen filter. But, still no cold air in the car.

Next check was the auxiliary fan, it does not come on with A/C, it does come on with output test in vcds, it came on once for about 3 seconds after I turned the engine off but nothing since.

I have checked all fuses but cannot see any problems.

Does anyone have any ideas where to look next or what needs testing?

Many thanks.
 

MattY376

Registered User
Hi Craig,


Forgive if this sounds stupid, but I know a few people who didn't realise this (myself included when I got my 2002 A4 Avant) , have you set the temp to LO, the econ button is econony mode not a/c

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MattY376

Registered User
Blowing frigid cold air as I type
1a8ef9a776fdd8993598424ef0970f4f.jpg


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Craig hopkins

Registered User
I have had it on LO but econ does initiate air con, econ light on means economy mode (air con compressor disengaged) econ light off means air con compressor is engaged and pumps the gasses round.
Was still luke warm on LO as well though.
 

Craig hopkins

Registered User
I don't think I have tried it off auto though with the top and bottom vents turn on so will try that and other vent set ups to see if anything changes.
 

MattY376

Registered User
Craig,

Every day is a school day. I was told it was not a/c related before. Interesting, your info makes sense.

I have noticed that the a/c in my A4 works best off Auto mode though.

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Craig hopkins

Registered User
Still no luck, had Halford check the gas and it's fine but the clutch doesn't seem to be kicking in. No rise in revs etc. Had a feel of the pulley and there is no movement round or back and forth, slight bit of play in a round motion but nothing else. All spins together when engine running including the bolt.
 

Craig hopkins

Registered User
Found a dodgy wire on the compressor connection, can't remember the colour (think it was brown) but it was the solid coloured wire, not the stripy one. Only a couple of strands connected the rest had freyed quite badly, have crimped them together but not sure how we'll as was in a rush but it still doesnt work anyway.
Also, can anyone confirm if there is supposed to be 2 washers between the metal plate and the shaft?
I managed to rotate the shaft by hand/spanner, wasn't easy but it did rotate. Not sure if that's a good or bad sign etc
 

Craig hopkins

Registered User
How do you get it to work like this, if my blowers are on, my econ light is too, i cant turn it off without turning it all off
If your econ light is on then something is stopping the air con from working, last time I had it the problem was with the ac high pressure sensor, second time I thought it just needed regassing but found other issues, and now my econ light is stuck on again. Next thing I'm trying is another regass.
Kwik fit are great for regassing as if it doesn't work they don't charge you.
 

MattY376

Registered User
How do you get it to work like this, if my blowers are on, my econ light is too, i cant turn it off without turning it all off
It's how it's always worked. My Econ switch has no effect on any other setting/s.

Perhaps as Craig says, there is an underlying issue somewhere within the system.

I'll have a look in the book and see if it says anything in the troubleshooting section.

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sauk538

Registered User
Does the A/C system take the same routes through all engines? Im assuming the pressure sensor is the one behind my NSF headlight? (RHD) I will take it to Kwik Fit when i can and see if i have any leaks then start tracing issues, already have a sensor, thanks for the advice
 

sauk538

Registered User
It's how it's always worked. My Econ switch has no effect on any other setting/s.

Perhaps as Craig says, there is an underlying issue somewhere within the system.

I'll have a look in the book and see if it says anything in the troubleshooting section.

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Also, unrelated to A/C but from my profile pic, does anyone know what the paint code could be for my car, looks very close/ same as yours MattY and Craig, thanks
 

MattY376

Registered User
Also, unrelated to A/C but from my profile pic, does anyone know what the paint code could be for my car, looks very close/ same as yours MattY and Craig, thanks
Mine is Atlas Grey ( paint code LY7Q )

Have a look under your rear bench seat, that's where my spec sticker is located (see just above White line in pic)
51b2f49b845c8b8724960c7fe55c722f.jpg


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sauk538

Registered User
Brilliant thanks, ill have a look, ive always been told its in the spare wheel well, ill see if i can diag my car too to see if there are any A/C faults logged and go from there
 

sauk538

Registered User
Mine is Atlas Grey ( paint code LY7Q )

Have a look under your rear bench seat, that's where my spec sticker is located (see just above White line in pic)
51b2f49b845c8b8724960c7fe55c722f.jpg


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Thank you for your help with the paint code, mine is the same colour as yours, i will diag my car later to see whats up with my A/C
 

sauk538

Registered User
I have diag'd my car and it is my high pressure switch, if i remove this from my car, will i loose gas if theres any in the system?
 

sauk538

Registered User
Brilliant thank you, will do it tonight if the weathers okay, hopefully thatll be problem solved
 

sauk538

Registered User
It says
High pressure sensor g65 short circuit to ground, i put in a second hand sensor today and my econ turns off with ignition on, but wont go off with engine on, A/C gets colder and colder but not cold enough (a little bit colder than econ on low) so will buy a new sensor at some point to rule that out completely, Coolant temp sensor was faulty when i got the car and the code said it was a short circuit but i changed the sensor and all is well, hoping its the same situation
 
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