audi a3 8l air con relay?

reptor245

reptor245

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So my woes continue...... Just got my car back from Halfords and they say my AC system is now all gassed up but still not pumping it through. He said if he pumps it through by hand it works fine (no idea what by hand means) . He said the compressor is working and the fuses are ok and to bring it back in next week to investigate the AC Relay?

My question is were abouts is the relay and what number is it? Thanks in advance
 
Check the 30A fuses on top of the battery

IMAG0657.jpg


They corrode and give a bad contact...
IMAG0658.jpg


If you have the AC on then both fans should be turning at low speed setting... if the fans are not running then the fuse is most likely the culprit... my fuse hadn't blown... was just a bad connection... cleaned it up and all was well again...

<tuffty/>
 
Would that account for the cold air not coming into the cabin from the AC? Just wondered why the guy at halfords said it was a relay issue? Were is the relay located?
 
While the Halfords guy might be right, never take your car there again please. It's like using Homer Simpson as your lawyer.
 
Don't know off hand... have you scanned for fault codes yet?

<tuffty/>
 
Thanks for the links tuffty, that's a lot of good info. Both my fans are working and had a very quick look at the fuse and looks like the picture you posted. Will clean it up over the weekend and try that. Thanks
 
Just thought though if both my fans are working then the fuse must be ok.
does anyone know the location and number of the air con relay please
 
Also would the pressure switch cause the ac not to flow into the cabin and if so how do I test the pressure switch??
 
Plausible... scan for fault codes though... aircon is the HVAC module in VCDS... if there is an issue with a sensor of something similar there should be a fault code there

<tuffty/>
 
Will scan it tmr to see if it throws any fault codes.

Does anyone no the location of the relay box? is it under the dash?
 
Update: Ive run VCDS-lite (only got the free version) and it comes up with this
Codes.jpg


Top image i already knew about as ive replaced the sensor but not cleared the codes.


The second image shows i have a coms error when trying to run the HVac section?

Managed to pull off the side panel and removed it to see if the relays are behind the fuses but they are not, just a wiring loom.
So again does anyone know were the A/C relay is located please?
 
Bunch of relays under the drivers side dash panel but no idea which one is the aircon one though...

I had a quick google around about the 'communications errors' and most suggest the cheap ebay leads can be at fault... the fact you can talk to other modules suggest that wiring could be an issue... turn off the aircon (it will still communicate) and any other thing like stereo etc to minimise potential for electrical noise and try HVAC module on its own.....

Ross Tech have an FAQ on comms issues
Ross-Tech: FAQ Page 2

<tuffty/>
 
Also having problems connecting to my Hvac unit, however on others no problem. Keen to see if the communication error can be resolved.
 
Not to sound like a nob but what dash panel? Already took off the side panel were the fuses are and then took off the 4 hex screws to put out the fuse tray to expose just the wiring looms. I'm at a loss to we're the relays are.

you mentioned my cons issue might be due to the ac being on and to turn everything off but I did that. I was on the car with the ignition lights on with no blowers on or radio or anything and still didn't work.
 
You have to remove the drivers side lower dash section...

This is a pic of a TT but its pretty much the same procedure and end result...
DSCF4500.jpg


Also... found this... its for a Passat it seems but VAG use the same bits across alot of their cars... and the relay number should be the same
passat-relay-panel.jpg


<tuffty/>
 
AHA i see now that the panel should drop down.. Will have another stab at it tmr :)
Thanks man
 
reptor245 said:
AHA i see now that the panel should drop down.. Will have another stab at it tmr :)
Thanks man
Click to expand...

It doesn't just drop down! lol You need to remove the headlight switch, then there's 4 torx head screws I think, maybe more? Then the whole thing pulls towards you and you can remove it totally.
 
There are 3 or 4 screws to undo behind the endpanel (will be obvious when you look) and 3 screws along the underside... one in top of the cubby hole, another the the left of the documents cubby (the one under the steering wheel) and one last one towards the back of the lower dash left had side again.... (T25 torx)

There are two metal clips one either side of the steering column where the lower dash panel meets the clocks... these need a sharp tug to release the lower dash panel from them (the lower dash panel has plastic lugs that locate into these metal clips...

You don't have to remove the headlight switch to do this but you will need to detach the wiring plugs of the light switch and unclip the OBD port to fully remove the lower dash panel out of the way... to remove the headlight switch though you push the switch in while its set to 'off' and turn clockwise... headlight buzzer may come on but once done (only turns a little) you should be able to pull the switch out and disconnect the wiring plugs from there... like I say I normally don't bother and just remove them once the panel is loose

<tuffty/>
 
I know this is an old thread, but hopefully someone can shed some light...

I'm trying to get to the bottom of my lack of air con. So far I have had a regas. The guy that refilled said that the system wasn't empty, so I presume there are no leaks. So far, I have replaced the fuse holder on top of battery, the fan control module under the battery and the pressure switch behind the heat shield at the back of the engine bay.

The guy that regassed it suggested that, although it spins, it might be the compressor due to the age of the vehicle. I'm trying to avoid the cost of a replacement compressor if I can help it. There are no fault codes with VAG-COM. Is there anything else I can try without shelling out too much?

Is the relay in the image @<tuffty/> posted the only relay to consider?

I also have an intermittent after run pump, which I'm convinced is related.

Thanks.
 
vanilla_ice said:
I know this is an old thread, but hopefully someone can shed some light...

I'm trying to get to the bottom of my lack of air con. So far I have had a regas. The guy that refilled said that the system wasn't empty, so I presume there are no leaks. So far, I have replaced the fuse holder on top of battery, the fan control module under the battery and the pressure switch behind the heat shield at the back of the engine bay.

The guy that regassed it suggested that, although it spins, it might be the compressor due to the age of the vehicle. I'm trying to avoid the cost of a replacement compressor if I can help it. There are no fault codes with VAG-COM. Is there anything else I can try without shelling out too much?

Is the relay in the image @<tuffty/> posted the only relay to consider?

I also have an intermittent after run pump, which I'm convinced is related.

Thanks.
Click to expand...
Can't honestly comment on the relays tbh... not an issue i have had personally.... I did recently replaced my pump as my aircon even after a regas was not working properly... fans were on etc but not really cold...

I bought this one...
www.ebay.co.uk

MAHLE ACP 191 000S COMPRESSOR AIR CONDITIONING | eBay

Find many great new & used options and get the best deals for MAHLE ACP 191 000S COMPRESSOR AIR CONDITIONING at the best online prices at eBay! Free delivery for many products.
www.ebay.co.uk

...and a new dryer...
www.ebay.co.uk

Air Conditioning dehumidifier 8FT351196-391 / AD 155 000S / 70818374 by Behr | eBay

Find many great new & used options and get the best deals for Air Conditioning dehumidifier 8FT351196-391 / AD 155 000S / 70818374 by Behr at the best online prices at eBay! Free delivery for many products.
www.ebay.co.uk

That sorted my shizz out

<tuffty/>
 
Thank you @<tuffty/>, I'll save them for later. Looks a good price for the compressor. Happy with quality etc.?

Did both items come with seals etc.? If I got the system de-gassed is the swap straight forward enough? I'm no mechanic, but happy to have a go at relatively simple removal and replace jobs. Guessing a ramp would make it easier?

After run pump is still a mystery...

Thanks again.
 
compressor came with seals, dryer didn't.... swap for me was easy enough but I did take the front off my car to do it as its basically easier plus now its a VR there is less room at the front anyway... did mine on axle stands... its in my thread here
www.audi-sport.net

My minor modding thread

Made some progress... had an issue with one of the GSF fans (new at the time of fitting the VR6 in)... I had been getting quite a large vibration from the fan when they were on and turns out that the larger fan was the culprit and the blade assembly had come loose ...so a bit of locktight...
www.audi-sport.net www.audi-sport.net

<tuffty/>
 
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I find the air con in our cars are actually quite loud specifically on the higher speed settings. Not sure if its because of the air con technology used on our cars at the time and they are renowned for being noisy? Did you notice an improvement in the sound levels when you replaced those parts?
 
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