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audi a3 8l air con relay?

Discussion in 'A3/S3 Forum (8L Chassis)' started by reptor245, Jun 21, 2013.

  1. reptor245
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    reptor245 Active Member

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    [Jun 21, 2013]
    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
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  3. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Jun 21, 2013]
    Check the 30A fuses on top of the battery

    [​IMG]

    They corrode and give a bad contact...
    [​IMG]

    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/>
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  4. reptor245
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    reptor245 Active Member

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    [Jun 21, 2013]
    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?
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  5. JudderMan
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    JudderMan Active Member

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    [Jun 21, 2013]
    While the Halfords guy might be right, never take your car there again please. It's like using Homer Simpson as your lawyer.
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  6. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Jun 21, 2013]
    Don't know off hand... have you scanned for fault codes yet?

    <tuffty/>
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  7. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Jun 21, 2013]
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  8. reptor245
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    reptor245 Active Member

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    [Jun 22, 2013]
    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
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  9. reptor245
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    reptor245 Active Member

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    [Jun 22, 2013]
    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
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  10. reptor245
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    reptor245 Active Member

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    [Jun 22, 2013]
    Also would the pressure switch cause the ac not to flow into the cabin and if so how do I test the pressure switch??
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  11. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Jun 22, 2013]
    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/>
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  12. reptor245
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    reptor245 Active Member

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    [Jun 24, 2013]
    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?
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  13. reptor245
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    reptor245 Active Member

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    [Jun 25, 2013]
    Update: Ive run VCDS-lite (only got the free version) and it comes up with this
    [​IMG]

    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?
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  14. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Jun 25, 2013]
    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/>
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  15. Gizmo20VT
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    Gizmo20VT Member

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    [Jun 25, 2013]
    Also having problems connecting to my Hvac unit, however on others no problem. Keen to see if the communication error can be resolved.
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  16. reptor245
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    reptor245 Active Member

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    [Jun 25, 2013]
    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.
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  17. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Jun 25, 2013]
    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...
    [​IMG]

    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
    [​IMG]

    <tuffty/>
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  18. reptor245
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    reptor245 Active Member

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    [Jun 25, 2013]
    AHA i see now that the panel should drop down.. Will have another stab at it tmr :)
    Thanks man
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  19. jojo
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    jojo S3 Drift King! Staff Member Moderator

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    [Jun 26, 2013]
    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.
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  20. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Jun 26, 2013]
    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/>
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  21. AJC
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    AJC 3rd Gear

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    [Jun 26, 2013]
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  22. Gizmo20VT
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    Gizmo20VT Member

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  23. Gizmo20VT
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    Gizmo20VT Member

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    [Jul 2, 2013]
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