Page 1 of 4 1234 LastLast
Results 1 to 25 of 82

Thread: HELP!! Aux fan comes on high as soon as car started

  1. #1
    Join Date
    Nov 2012
    Location
    Lewes,DE
    Posts
    1,120
    My Cars
    1997 540i

    HELP!! Aux fan comes on high as soon as car started

    Ok guys please help 97 540i auto, as soon as i turn key on fuse 7 blows i have gone trough 5 of them , so i put in a 30 amp and now aux fan is just coming on whenever i turn key it comes on high! So i removed the low speed relay and fan turns off, low speed resistor and high speed are both bypassed. Its bot a bad temp switch either cause that is not even plugged in . I removed high speed relay for aux fan and the fan is still
    Stuck on high
    Electric Fan conversion, 840Ci thermostat, Dinan style CAI,de-screened MAF, Dinan transmission chip, 255lph LS1 fuel pump, drilled slotted rotors, 3.15 differential, Bel rx65 radar (hard-wired). Hemi Killer!

  2. #2
    Join Date
    Oct 2010
    Location
    San Jose, CA
    Posts
    11,537
    My Cars
    1997 BMW 540i 6 speed
    There are three relays that control the fan. K21, in the E-box, is the low-speed (or Stage 1) relay. It pulls in when the A/C is activated, or when the dual temp switch on the rad reads 91 deg C. The switch provides a ground for the coil.

    If F7 blows, the relay coil, or the IHKA panel, is bad. Not a good idea to install bigger fuses.

    K22 , in the glovebox, is the medium speed (or Stage 2) relay, and is controlled by the high pressure switch.

    K201, in the E-box, is the high speed relay (or Stage 3) is controlled by the dual temp switch (104 deg C) on the rad.


    Ed in San Jose '97 540i 6 speed aspensilber over aubergine leather. Build date 3/97. Golden Gate Chapter BMW CCA Nr 62319.

  3. #3
    Join Date
    Nov 2012
    Location
    Lewes,DE
    Posts
    1,120
    My Cars
    1997 540i
    Quote Originally Posted by edjack View Post
    There are three relays that control the fan. K21, in the E-box, is the low-speed (or Stage 1) relay. It pulls in when the A/C is activated, or when the dual temp switch on the rad reads 91 deg C. The switch provides a ground for the coil.

    If F7 blows, the relay coil, or the IHKA panel, is bad. Not a good idea to install bigger fuses.

    K22 , in the glovebox, is the medium speed (or Stage 2) relay, and is controlled by the high pressure switch.

    K201, in the E-box, is the high speed relay (or Stage 3) is controlled by the dual temp switch (104 deg C) on the rad.
    I have swapped k201 relay with several other good ones yet fuse 7 keeps blowing
    Electric Fan conversion, 840Ci thermostat, Dinan style CAI,de-screened MAF, Dinan transmission chip, 255lph LS1 fuel pump, drilled slotted rotors, 3.15 differential, Bel rx65 radar (hard-wired). Hemi Killer!

  4. #4
    Join Date
    Nov 2012
    Location
    Lewes,DE
    Posts
    1,120
    My Cars
    1997 540i
    Why does fuse 7 keep blowing ? If i put a 30 amp in then the aux fan is stuck on high without ac even being on !!

  5. #5
    Join Date
    Dec 2013
    Location
    Chicagoland area
    Posts
    4,372
    My Cars
    EXOTICS
    Quote Originally Posted by edjack View Post
    There are three relays that control the fan. K21, in the E-box, is the low-speed (or Stage 1) relay. It pulls in when the A/C is activated, or when the dual temp switch on the rad reads 91 deg C. The switch provides a ground for the coil.

    If F7 blows, the relay coil, or the IHKA panel, is bad. Not a good idea to install bigger fuses.

    K22 , in the glovebox, is the medium speed (or Stage 2) relay, and is controlled by the high pressure switch.

    K201, in the E-box, is the high speed relay (or Stage 3) is controlled by the dual temp switch (104 deg C) on the rad.
    Answer is already there.

  6. #6
    Join Date
    Nov 2012
    Location
    Lewes,DE
    Posts
    1,120
    My Cars
    1997 540i
    Quote Originally Posted by MIKYZZ4 View Post
    Answer is already there.
    What is the answer?? I need to know what to start testing. Someone on another forum mentioned the relay socket contacts maybe welded together? I really need help on this
    Electric Fan conversion, 840Ci thermostat, Dinan style CAI,de-screened MAF, Dinan transmission chip, 255lph LS1 fuel pump, drilled slotted rotors, 3.15 differential, Bel rx65 radar (hard-wired). Hemi Killer!

  7. #7
    JimLev's Avatar
    JimLev is offline Artifically Aspirated Moderator
    Join Date
    Oct 2006
    Location
    Sundance Mesa, NM
    Posts
    19,817
    My Cars
    00 540/6, '16 Highlander
    Just replied to your PM.
    Pull the high speed relay out and then see if F7 still blows.
    Report back in this thread so we can keep track of what has been done.

  8. #8
    Join Date
    Oct 2010
    Location
    San Jose, CA
    Posts
    11,537
    My Cars
    1997 BMW 540i 6 speed
    He said he's already swapped out the HS relay, K201, unless he's confused.

    I believe K201 is buried under the cables and wires; not visible.


    Ed in San Jose '97 540i 6 speed aspensilber over aubergine leather. Build date 3/97. Golden Gate Chapter BMW CCA Nr 62319.

  9. #9
    Join Date
    Nov 2012
    Location
    Lewes,DE
    Posts
    1,120
    My Cars
    1997 540i
    Quote Originally Posted by edjack View Post
    He said he's already swapped out the HS relay, K201, unless he's confused.

    I believe K201 is buried under the cables and wires; not visible.
    no i swapped out the low speed relay several times. I then added a 30 amp fuse in place of the 20 amp F7 fuse and the aux fan would just run on high as soon as i turned the key on. So i pulled the high speed relay and it kept running, so i then pulled the low speed relay out completely and it stopped. Jim, im going to try what u said and pull the high speed relay, then put in a new 20 amp fuse and turn the key on. Will keep u updated! Thank you for responding!
    Electric Fan conversion, 840Ci thermostat, Dinan style CAI,de-screened MAF, Dinan transmission chip, 255lph LS1 fuel pump, drilled slotted rotors, 3.15 differential, Bel rx65 radar (hard-wired). Hemi Killer!

  10. #10
    Join Date
    Mar 2017
    Location
    Nowhere
    Posts
    223
    My Cars
    something
    You forgot to mention what you put in another post which may have something to do with your issues.

    "I just added a toggle switch by splicing into the blck/gray wire on the radiator sensor. It worked one time and now everytime i turn ignition on the fuse 7 blows! so i added a 30 amp fuse for testing purposes and now when ever i turn the key on the aux fan goes on high! this is without ac on. WTH is going on? where do i begin to start testing this thing? if i remove the low speed relay the fan stops, i removed the high speed relay first but fan kept running."

    It appears you may have blown the IHKA panel depending on where you pulled the power for the toggle switch.

  11. #11
    Join Date
    Nov 2012
    Location
    Lewes,DE
    Posts
    1,120
    My Cars
    1997 540i
    Quote Originally Posted by Uturn540 View Post
    You forgot to mention what you put in another post which may have something to do with your issues.

    "I just added a toggle switch by splicing into the blck/gray wire on the radiator sensor. It worked one time and now everytime i turn ignition on the fuse 7 blows! so i added a 30 amp fuse for testing purposes and now when ever i turn the key on the aux fan goes on high! this is without ac on. WTH is going on? where do i begin to start testing this thing? if i remove the low speed relay the fan stops, i removed the high speed relay first but fan kept running."

    It appears you may have blown the IHKA panel depending on where you pulled the power for the toggle switch.

    I tapped into the black/grey high speed ground wire at the double temp switch on the radiator. I was using the A/c today no problem with the aux fan unplugged of course, the main harness unplugged. What is the IHKA panel? where is it located cause the panel in the dash works just fine.
    Electric Fan conversion, 840Ci thermostat, Dinan style CAI,de-screened MAF, Dinan transmission chip, 255lph LS1 fuel pump, drilled slotted rotors, 3.15 differential, Bel rx65 radar (hard-wired). Hemi Killer!

  12. #12
    Join Date
    Dec 2013
    Location
    Chicagoland area
    Posts
    4,372
    My Cars
    EXOTICS
    Hidden modifications just add to the confusion OP,
    Uturn just brought it to light, thanks UT540!

  13. #13
    Join Date
    Nov 2012
    Location
    Lewes,DE
    Posts
    1,120
    My Cars
    1997 540i
    Quote Originally Posted by MIKYZZ4 View Post
    Hidden modifications just add to the confusion OP,
    Uturn just brought it to light, thanks UT540!
    SO if there is something that you know, why dont u just tell me? help a fellow member out man.
    Electric Fan conversion, 840Ci thermostat, Dinan style CAI,de-screened MAF, Dinan transmission chip, 255lph LS1 fuel pump, drilled slotted rotors, 3.15 differential, Bel rx65 radar (hard-wired). Hemi Killer!

  14. #14
    Join Date
    Nov 2012
    Location
    Lewes,DE
    Posts
    1,120
    My Cars
    1997 540i
    IMG_0527.JPG
    Quote Originally Posted by ninetyseven1 View Post
    I tapped into the black/grey high speed ground wire at the double temp switch on the radiator. I was using the A/c today no problem with the aux fan unplugged of course, the main harness unplugged. What is the IHKA panel? where is it located cause the panel in the dash works just fine.
    Also guys, look at the picture attached. About a month ago i had a ground issue with the low speed relay socket , aux fan wouldnt come on when ac button pressed , SO that wire 85 from the relay socket has been cut and grounded to the body of the car, it comes right out of the relay socket and just goes to ground. If that makes any difference at all.
    Electric Fan conversion, 840Ci thermostat, Dinan style CAI,de-screened MAF, Dinan transmission chip, 255lph LS1 fuel pump, drilled slotted rotors, 3.15 differential, Bel rx65 radar (hard-wired). Hemi Killer!

  15. #15
    Join Date
    Dec 2013
    Location
    Chicagoland area
    Posts
    4,372
    My Cars
    EXOTICS
    Sorry,
    I'm not attempting to seem like a know it all,
    but all of us can seem to know nothing,
    when unknown modifications are thrown into the mix!

  16. #16
    Join Date
    Dec 2013
    Location
    Chicagoland area
    Posts
    4,372
    My Cars
    EXOTICS
    From my understanding of the fans triggers,
    the DME/ECU provide the ground activations,
    I could be wrong.

  17. #17
    JimLev's Avatar
    JimLev is offline Artifically Aspirated Moderator
    Join Date
    Oct 2006
    Location
    Sundance Mesa, NM
    Posts
    19,817
    My Cars
    00 540/6, '16 Highlander
    Quote Originally Posted by MIKYZZ4 View Post
    From my understanding of the fans triggers,
    the DME/ECU provide the ground activations,
    I could be wrong.
    For the non tu engine......
    The Temp switch on the side of the radiator and/or the HVAC provides the ground for low speed operation.
    For Hi speed ground is provided but the Temp switch.
    For Mid speed the pressure switch provides ground.

    On a tu engine the aux fan would be controlled by the DME.
    Last edited by JimLev; 06-19-2018 at 09:53 AM. Reason: added clarification non tu vs tu aux fan operation

  18. #18
    Join Date
    Dec 2013
    Location
    Chicagoland area
    Posts
    4,372
    My Cars
    EXOTICS
    Thanks for the clarification Jim!

  19. #19
    Join Date
    Nov 2012
    Location
    Lewes,DE
    Posts
    1,120
    My Cars
    1997 540i
    Jim I tried what suggested and pulled high speed relay out and the fuse 7 blew as soon as I turned the key on again

  20. #20
    Join Date
    Dec 2013
    Location
    Chicagoland area
    Posts
    4,372
    My Cars
    EXOTICS
    Remove your modifications,
    The temp switch or the IHKA is faulty!

  21. #21
    Join Date
    Nov 2012
    Location
    Lewes,DE
    Posts
    1,120
    My Cars
    1997 540i
    Quote Originally Posted by MIKYZZ4 View Post
    Remove your modifications,
    The temp switch or the IHKA is faulty!
    i removed that switch immediately after that happene the first time! the low speed relay has always had terminal 85 going straight to the car body as a ground, and when i did attempt to install that toggle switch for the high speed i cut the wire at the temp switch and connected it to my toggle. So the temp switch black and gray high speed wire was just hanging off of the temp sensor.
    Electric Fan conversion, 840Ci thermostat, Dinan style CAI,de-screened MAF, Dinan transmission chip, 255lph LS1 fuel pump, drilled slotted rotors, 3.15 differential, Bel rx65 radar (hard-wired). Hemi Killer!

  22. #22
    Join Date
    Dec 2013
    Location
    Chicagoland area
    Posts
    4,372
    My Cars
    EXOTICS
    I see,
    well then, what does that leave to consider,
    as to the cause of fuse #7 blown?

  23. #23
    Join Date
    Nov 2012
    Location
    Lewes,DE
    Posts
    1,120
    My Cars
    1997 540i
    Quote Originally Posted by MIKYZZ4 View Post
    I see,
    well then, what does that leave to consider,
    as to the cause of fuse #7 blown?
    You tell me. Thats what helping each other is all about.
    Electric Fan conversion, 840Ci thermostat, Dinan style CAI,de-screened MAF, Dinan transmission chip, 255lph LS1 fuel pump, drilled slotted rotors, 3.15 differential, Bel rx65 radar (hard-wired). Hemi Killer!

  24. #24
    Join Date
    Dec 2013
    Location
    Chicagoland area
    Posts
    4,372
    My Cars
    EXOTICS
    OK,
    #1.
    It appears you may have blown the IHKA panel depending on where you pulled the power for the toggle switch.
    #2.
    If F7 blows, the relay coil, or the IHKA panel, is bad. Not a good idea to install bigger fuses.
    Sorry to be so blunt, but you're insisting!

  25. #25
    JimLev's Avatar
    JimLev is offline Artifically Aspirated Moderator
    Join Date
    Oct 2006
    Location
    Sundance Mesa, NM
    Posts
    19,817
    My Cars
    00 540/6, '16 Highlander
    Quote Originally Posted by MIKYZZ4 View Post
    Remove your modifications,
    The temp switch or the IHKA is faulty!
    Yes, disconnect the switch you added.....then.....
    If F7 still blows pull out the low speed relay.
    If F7 still blows then the you have a short somewhere between F7 and the relay socket.
    If F7 doesn't blow then you have a short between the relay socket and the resistors mounted on the fan frame.

Page 1 of 4 1234 LastLast

Similar Threads

  1. Help: Aux Fan on high when lights are on
    By Jdotsturn in forum 1996 - 2003 (E39)
    Replies: 8
    Last Post: 08-08-2011, 06:27 AM
  2. HELP! aux fan resistor not found URGENT!!!
    By SleekBMW in forum 1996 - 2003 (E39)
    Replies: 14
    Last Post: 09-15-2009, 06:59 AM
  3. Help! Aux Fan Switch?
    By goyongj in forum 1991 - 1999 (E36)
    Replies: 5
    Last Post: 07-02-2006, 08:26 PM
  4. Help! Aux Fan problem; no fuse #40?
    By Nivola in forum 1996 - 2002 Z3 (E36/7, E36/8)
    Replies: 3
    Last Post: 05-26-2005, 05:30 PM
  5. aux fan comes when car is cold
    By westcp in forum 1991 - 1999 (E36)
    Replies: 1
    Last Post: 11-12-2004, 06:39 PM

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
  •