Audizine - An Automotive Enthusiast Community

Results 1 to 11 of 11
  1. #1
    Active Member Two Rings
    Join Date
    Nov 22 2014
    AZ Member #
    296898
    My Garage
    1960 Corvette
    Location
    Norway

    ac fan runs continuous after engine is turned off

    Guest-only advertisement. Register or Log In now!
    Car: 2000 A6 2,7t quattro avant.

    I've had some issues with the ac condenser fan(the one on the front of the radiators) going on and off after driving, today a did a small trip, filling the tires. Then I noticed the ac condenser fan going on and off continuosly while I was getting correct tire pressure.(engine was on). then I drove back home, engine got to normal working temp.

    After shutting the car off the ac condenser fan where in high mode for 15minutes after turning engine off.(previously it have gone in high mode and then off, and high mode for a long time)

    I've searched some and there seem to be a lot of different things that could cause this.

    1. the aux fan on the rear of the radiators doesn't work(worn out brushes f.ex)
    2. faulty fan control module
    3. faulty relay
    4. fan temp switch?
    5. aux water pump not working?

    Going to check if the aux fan works, and the fcm, since it turned off in the end I'm guessing the temp switch works, any chance the relay is acting up?

    Anyone experienced the same and have some inputs?
    -----------------------------------------------
    2000 Audi A6 Avant 2.7T Quattro
    1960 Chevrolet Corvette

  2. #2
    Veteran Member Four Rings PaperToast's Avatar
    Join Date
    Apr 29 2009
    AZ Member #
    41811
    My Garage
    Quadzilla
    Location
    Longmont, CO

    im guessing its the front fan on the driver side of the radiator?
    if so, it sounds like the after run working like it should
    Rockin' the Rockies
    '01 allroad, 240k woot woot, still boosting on original turbos and tippy, slightly more modified. . .

    Scotty@Advanced, "Push it off a cliff, when it hits the ground you should have a few thousand horsepower available for a brief second."

  3. #3
    Active Member Two Rings
    Join Date
    Nov 22 2014
    AZ Member #
    296898
    My Garage
    1960 Corvette
    Location
    Norway

    Quote Originally Posted by PaperToast View Post
    im guessing its the front fan on the driver side of the radiator?
    if so, it sounds like the after run working like it should
    Yes, the one in front of the radiators, driver side(left) between bumper and radiator..

    If that's the normal operation mode it hasn't worked like it should earlier...

    What's the normal working mode for that one? Does the aux pump also run when that runs? Is it controlled by the thermal switch on the driver side of the engine?
    -----------------------------------------------
    2000 Audi A6 Avant 2.7T Quattro
    1960 Chevrolet Corvette

  4. #4
    Active Member Two Rings
    Join Date
    Nov 22 2014
    AZ Member #
    296898
    My Garage
    1960 Corvette
    Location
    Norway

    Took a longer drive today, so that even the oil got up to working temp.

    Checked the ECON mode on ac, both fans turned off, turned off econ, and both fans turned on.

    After parking the ac condenser fan spun at a low speed, seems more normal.

    So I guess something is a bit strange, found this: https://www.audiforums.com/forum/aud...-fixed-215239/ thinking that the fan switch is somewhat faulty.. have ordered a new one, will se if that fixes the issue. Switch: 357919369F
    -----------------------------------------------
    2000 Audi A6 Avant 2.7T Quattro
    1960 Chevrolet Corvette

  5. #5
    Established Member Two Rings ChanceA4Parks's Avatar
    Join Date
    Jan 23 2018
    AZ Member #
    412884
    Location
    Ridgeland, MS 39157

    I had the same issue earlier this year and it ended up being moisture in my ecu box. Once I dried the water up, the fan no longer ran the battery down by running all night.

    Sent from my SM-N950U1 using Audizine mobile app

  6. #6
    Active Member Two Rings
    Join Date
    Nov 22 2014
    AZ Member #
    296898
    My Garage
    1960 Corvette
    Location
    Norway

    Quote Originally Posted by ChanceA4Parks View Post
    I had the same issue earlier this year and it ended up being moisture in my ecu box. Once I dried the water up, the fan no longer ran the battery down by running all night.

    Sent from my SM-N950U1 using Audizine mobile app
    I've checked the box with the ecu, after googling many said the relay under there could be moist or filled with water. But in the ecu box on my car there is only the ecu, and it was nice and dry, all the relays are inside the car. Did you open the ecu and dry it or only the box containing the ecu?

    Last edited by sailor83; 11-09-2018 at 10:21 AM. Reason: added photo
    -----------------------------------------------
    2000 Audi A6 Avant 2.7T Quattro
    1960 Chevrolet Corvette

  7. #7
    Established Member Two Rings ChanceA4Parks's Avatar
    Join Date
    Jan 23 2018
    AZ Member #
    412884
    Location
    Ridgeland, MS 39157

    The main thing that fixed my issue was keeping compressed air on the harness and plug going into the ecu for a little while. Basically forcing any water out of the wiring and connectors.

    Sent from my SM-N950U1 using Audizine mobile app

  8. #8
    Veteran Member Four Rings PaperToast's Avatar
    Join Date
    Apr 29 2009
    AZ Member #
    41811
    My Garage
    Quadzilla
    Location
    Longmont, CO

    Quote Originally Posted by sailor83 View Post
    Yes, the one in front of the radiators, driver side(left) between bumper and radiator..

    If that's the normal operation mode it hasn't worked like it should earlier...

    What's the normal working mode for that one? Does the aux pump also run when that runs? Is it controlled by the thermal switch on the driver side of the engine?
    how its supposed to work is that it runs for 5-10 min after the car has been driven, and only after it reaches a certain temp
    and yes the aux pump runs, that's the whole point of the after run
    and yes there is a thermo switch on the driver side rear of the engine that controls it

    there is a module underneath the driver side headlight that controls all the fans, but id tackle that after ruling out the thermo switches
    Rockin' the Rockies
    '01 allroad, 240k woot woot, still boosting on original turbos and tippy, slightly more modified. . .

    Scotty@Advanced, "Push it off a cliff, when it hits the ground you should have a few thousand horsepower available for a brief second."

  9. #9
    Active Member Two Rings
    Join Date
    Nov 22 2014
    AZ Member #
    296898
    My Garage
    1960 Corvette
    Location
    Norway

    Quote Originally Posted by PaperToast View Post
    how its supposed to work is that it runs for 5-10 min after the car has been driven, and only after it reaches a certain temp
    and yes the aux pump runs, that's the whole point of the after run
    and yes there is a thermo switch on the driver side rear of the engine that controls it

    there is a module underneath the driver side headlight that controls all the fans, but id tackle that after ruling out the thermo switches
    Thanks!

    Something is fishy when it runs on full speed for 15minutes when the oil havent got any temp, only the water. And it varies in behaviour. So I've ordered the thermo switch after reading about the symptoms of another guy, seems like the same issues on my car.

    Now I know where the fcm module is, guessing it's a box with some circuitry and some relays, and relays are known to wear out.

    Back to my list:
    1. the aux fan on the rear of the radiators doesn't work(worn out brushes f.ex) <- This works
    2. faulty fan control module <- Probably ok
    3. faulty relay <- Probably ok, standard 4pin 40A relay, ordered a new one.
    4. fan temp switch? <- intermittent fault with this one perhaps, replacing this first to see.
    5. aux water pump not working? <- haven't check this one, need to find where it is connected so I can hotwire it to check.
    -----------------------------------------------
    2000 Audi A6 Avant 2.7T Quattro
    1960 Chevrolet Corvette

  10. #10
    Veteran Member Four Rings PaperToast's Avatar
    Join Date
    Apr 29 2009
    AZ Member #
    41811
    My Garage
    Quadzilla
    Location
    Longmont, CO

    aux pump is under the intake manifold . . .
    Rockin' the Rockies
    '01 allroad, 240k woot woot, still boosting on original turbos and tippy, slightly more modified. . .

    Scotty@Advanced, "Push it off a cliff, when it hits the ground you should have a few thousand horsepower available for a brief second."

  11. #11
    Active Member Two Rings
    Join Date
    Nov 22 2014
    AZ Member #
    296898
    My Garage
    1960 Corvette
    Location
    Norway

    Quote Originally Posted by PaperToast View Post
    aux pump is under the intake manifold . . .
    I know, so need to find the cable, easier to hotwire that instead of taking half the engine apart :P Could be faulty brushes as the car has 280k-km on the counter..

    So if the auxillary pump doesn't run when it's supposed to, will the ac condenser fan then automatically go to full speed?
    Last edited by sailor83; 11-11-2018 at 02:34 AM. Reason: added info
    -----------------------------------------------
    2000 Audi A6 Avant 2.7T Quattro
    1960 Chevrolet Corvette



Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


    © 2001-2018 Audizine, Audizine.com, and Driverzines.com
    Audizine is an independently owned and operated automotive enthusiast community and news website.
    Audi and the Audi logo(s) are copyright/trademark Audi AG. Audizine is not endorsed by or affiliated with Audi AG.