Announcement

Collapse
No announcement yet.

Aux fan in high instead of low wiring question

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Aux fan in high instead of low wiring question

    So I removed the clutch fan and using the aux fan as a cooling fan. My AC is also removed. I just installed a m42 80 c aux temp sensor but the low setting is not cooling enough for my comfort. I would like the aux fan to turn on high instead of low. I know the black wire is ground but not too sure about the other two. Do i just cut the two colored wires and switch them?



    Sent from my SM-J700T using Tapatalk
    Bought parts from me before? leave your feedback here


    #2
    Dont cut the wire. You can open up the connector with a small screwdriver and switch the wires for the high and low speeds.

    Or if you want full control over when the aux fan turns on, you can route some wire from the connector, along the engine bay, into the glove box and then to a fog light switch above the radio.

    Make sure you double check which wire is actually ground. Cant remember if its the black wire or the brown/black wire.
    Last edited by jhaurimn; 03-19-2017, 03:15 AM.
    Current:
    1989 325i
    1988 M3
    1987 325ic
    Past:
    2001 330ci
    2001 M3

    Comment


      #3
      Originally posted by jhaurimn View Post
      Dont cut the wire. You can open up the connector with a small screwdriver and switch the wires for the high and low speeds.

      Or if you want full control over when the aux fan turns on, you can route some wire from the connector, along the engine bay, into the glove box and then to a fog light switch above the radio.

      Make sure you double check which wire is actually ground. Cant remember if its the black wire or the brown/black wire.
      Awesome. Thanks, you saved me from cutting my wires. I'll double check to see which one is ground.

      Sent from my SM-J700T using Tapatalk
      Bought parts from me before? leave your feedback here

      Comment


        #4
        If you still have the ac button on your dash, just leave it pushed in.

        The aux fan is supposed to go straight to high speed when ac is on. Give it a try first.
        Originally posted by codyep3
        I hope to Christ you have looks going for you, because you sure as fuck don't have any intelligence.
        2001 silver/Blk 325 cabby. SOLD
        1988 Blk/Blk e30 factory wide body kit car SOLD
        1992 DS/BLK 325 m-tech II apperance pack cabby SOLD!
        2002 325xit Sil/blk. SOLD
        2012 328i xdrive touring. Wht/blk. SOLD
        2009 135 cabby. monacoblue/blk leather SOLD
        2007 Z4m coupe. Silver grey/black/ aluminum. 1of50
        2010 F650gs twin
        2016 M235i cabby. Mineral grey/Red leather

        Comment


          #5
          Don't switch those wires. If you do switch them, yes the fan will come on high at a lower temp, but then the fan will switch on to the slower speed if the temperature gets hot enough. Also, pretty sure that the green wire is the one you want to leave where it is, not the black one. I don't have a wiring diagram in front of me right now, but I believe that the wire in the center is the common wire in the switch.

          Edit: Keep reading, I retract part of this after Tod Black gives us the wiring diagram.
          Last edited by YosemiteSam; 03-20-2017, 04:25 PM.
          sigpic

          Comment


            #6
            Originally posted by YosemiteSam View Post
            Don't switch those wires. If you do switch them, yes the fan will come on high at a lower temp, but then the fan will switch on to the slower speed if the temperature gets hot enough. Also, pretty sure that the green wire is the one you want to leave where it is, not the black one. I don't have a wiring diagram in front of me right now, but I believe that the wire in the center is the common wire in the switch.
            If the high doesn't cool down the motor, there will be no use for the low anyway. I just found out the black is not ground, but instead it's for the low. So from your post, the green is ground? Or the black/brown?

            Sent from my SM-J700T using Tapatalk
            Bought parts from me before? leave your feedback here

            Comment


              #7
              Originally posted by Todd Black 88 View Post
              If you still have the ac button on your dash, just leave it pushed in.

              The aux fan is supposed to go straight to high speed when ac is on. Give it a try first.
              I still have the ac button, but i recall reading somewhere that the ac button won't turn on the aux fan if the dryer is removed. My ac components have been all removed.

              Sent from my SM-J700T using Tapatalk
              Bought parts from me before? leave your feedback here

              Comment


                #8
                Yeah, if you are going to switch them, switch the black and black/brown. The green wire is either power or ground, but based on bmw's normal wiring, it is probably ground.
                sigpic

                Comment


                  #9
                  I was wrong, it would only bring on low speed.

                  Here.
                  Originally posted by codyep3
                  I hope to Christ you have looks going for you, because you sure as fuck don't have any intelligence.
                  2001 silver/Blk 325 cabby. SOLD
                  1988 Blk/Blk e30 factory wide body kit car SOLD
                  1992 DS/BLK 325 m-tech II apperance pack cabby SOLD!
                  2002 325xit Sil/blk. SOLD
                  2012 328i xdrive touring. Wht/blk. SOLD
                  2009 135 cabby. monacoblue/blk leather SOLD
                  2007 Z4m coupe. Silver grey/black/ aluminum. 1of50
                  2010 F650gs twin
                  2016 M235i cabby. Mineral grey/Red leather

                  Comment


                    #10
                    There is no ground in those wires. One of them is 12v which they switch between.

                    On another note, low speed should be more than adequate to cool it. The stock aux fan is probably a bit crap as it is made for a/c not the radiator. I got a $20 e39 fan from the scrap yard and it cools easily on low speed.


                    T U R B O - M 2 0 - B U I L D

                    M U S C C O O

                    Comment


                      #11
                      During idle in outside 63 degree temperature.

                      This is when the low fan starts to kick in at 80c. Low fan stay on as long as the car stay idling.


                      After switching the brown/black wire with black wire so the high fan start at 80c instead of low fan.


                      Fan stay on for couple minutes and stop. It will turn back on after couple minutes of downtime.


                      After high fan stop


                      Im my observation, during idling in ~60 degree temp, I found that with the high fan on, the temp needle never goes pass the middle mark. In low setting, the temp needle goes about half way between the middle mark and 3/4 line.

                      When the car is moving, the fan is never on or should never be on unless the car is overheating due to a bad water pump, air bubble, blown head, ects. The fan only turn on during idling.

                      With the clutch fan deleted, the car do pick up faster, and less noisy. When the car is already moving (over ~20 mph), power feel about the same.

                      Sent from my SM-J700T using Tapatalk
                      Last edited by mr.vang; 04-04-2017, 12:46 AM.
                      Bought parts from me before? leave your feedback here

                      Comment


                        #12
                        Originally posted by potatomash View Post
                        There is no ground in those wires. One of them is 12v which they switch between.

                        On another note, low speed should be more than adequate to cool it. The stock aux fan is probably a bit crap as it is made for a/c not the radiator. I got a $20 e39 fan from the scrap yard and it cools easily on low speed.
                        I figured it out after looking at the diagram. No ground but a power source only.

                        Is the e39 aux fan bigger and push in more air?

                        Sent from my SM-J700T using Tapatalk
                        Bought parts from me before? leave your feedback here

                        Comment


                          #13
                          Originally posted by YosemiteSam View Post
                          Yeah, if you are going to switch them, switch the black and black/brown. The green wire is either power or ground, but based on bmw's normal wiring, it is probably ground.
                          Thank you

                          Sent from my SM-J700T using Tapatalk
                          Bought parts from me before? leave your feedback here

                          Comment


                            #14
                            Exactly the wiring diagram I was talking about. I was incorrect with my first post, switching the wires is definitely the way to do it. The higher temperature switch does not disengage the lower switch, so the fan will just stay on high.
                            sigpic

                            Comment

                            Working...
                            X