Ok. I replaced the one in the hose but my car is broken so I haven't had a chance to test it out yet. Simple install.
1999 540iT: aFe Intake | M60 Intake | DUDMD Tune | Bavauto Springs | Bavsound Stage 1
2006 X5 3.0
Its 47F outside now. I started her up. Turned A/C on. AUX Fan is NOT engaging.
Does it mean I have a problem?
BMW CCA 434493
Again, excellent write up!
In my case, as long as I remember, AUX fan was operating only on HIGH. Either HIGH and LOUD or nothing.
So that probably was cause by one or both faulty resistors?
Now my AUX fan is not coming on at all.
Removing bumper is not an issue.I did it already couple times.
I just wanna know if its possible to jump the motor without removing anything?
Thanks again,
siny528i
BMW CCA 434493
Hey guys!
My fuses are Ok!
I also jumped the AUX fan and it was spinning on HIGH:
Does it point me to BAD Resistors?
BTW, those Resistors aren't cheap. In average they go for about $175. Far from what RealOEM shows.
I found one at ECSTunning for $32.90 made by MTC. Sounds like a steal.
What do you think?
TIA
siny528i
BMW CCA 434493
Does the a/c holds charge? If it does, why change it, we arein winter right now
e30 325i, the mighty 4 door granma mobile....Gone
e39 528i, 4 door sports tank
Last edited by siny528i; 12-30-2015 at 08:49 PM.
BMW CCA 434493
Shouldn't be too hard, since you will be removing the bumper and all the stuff to replace the fan. You will need to unbolt the refrigerant lines. What i am not sure is if it comes out thru the front (easy) or thru the back ( remove rediator, engine fan, etc)
And Happy New Years to you also!!!
e30 325i, the mighty 4 door granma mobile....Gone
e39 528i, 4 door sports tank
Hey guys,
Happy New Year!
I just installed complete BEHR A/C Condenser Fan Assembly, BUT it shows no signs of life.
All fuses are fine. Where else I should look for?
TIA
siny528i
BMW CCA 434493
Apply fresh 12V to the Aux Fan and see what happens.
Hello guys,
Here's what I ve learned (thanks edjack from UnofficialBMW and Jim Cash from RoadFly) with some of my editing:
Double Temperature Switch 91/104CEL (located on Radiator) activates the AUX Fan when coolant reaches above average temperatures:
91C - Low speed
104C - High Speed
AUX Fan operates on 3 modes: LOW, MEDIUM and HIGH.
NOTE: Newer E39's may have a variable speed fan and these tips may not be exactly what you're looking for.
These tips are accurate for troubleshooting a 1998 540iA with a Nov 97 build date.
AUX Fan comes on at LOW mode/speed whenever the AC is ON by an input from the AC controller and the engine computer combined AND the outdoor temp is above 10C - as shown on the display in the instrument cluster AND it supposed to stay on ALL THE TIME.
Two days ago in order to check my newly installed AUX Fan I:
- Disconnected the 3 wire harness that goes to the Double Temperature Switch 91/104CEL (located on Radiator):
- Started the car;
- Using small paper clip...
...I connected BROWN wire to the BLACK wire with RED Stripe - AUX Fan started to spin at MEDIUM speed;
- Then I connected the BROWN wire to the BLACK wire with the WHITE Stripe - AUX Fan started to spin at HIGH speed;
- Shut the car down and reconnected the harness to the switch.
By jumpering at that point you are operating the relays that provide the power source to the fan.
Relays are in the E box (under the passenger side microfilter).
So my AUX Fan is Ok, but I wish I knew this trick and used it on my OLD one...
IF the Aux fan did NOT run at any speed, then I would first suspect that a fuse is blown.
IF you've checked the fuses then motor may have failed.
IF the AUX Fan only worked on the highest speed, then I would suspect that one or both of the resistors or relays that control the lower speeds have failed (no resistors are used for the highest speed, but a relay is).The resistors that control the lower speeds are located on the AUX Fan Assembly.
IF you are experiencing overheating and the fan worked flawlessly, maybe the temp sensor (the one that you disconnected to jump wires at) has failed.
PS. Yesterday morning it was moderate outside. About 52F. I started the car and my AUX Fan went ON at LOW speed.
I saw its spinning like this first time since I bought my car in 2007. Or maybe I've never noticed...
BMW CCA 434493
I have overheating issues, the aux fan does not turn on with AC, but does run only on high when jumped at temp switch (on radiator) connector. I replaced the temp sensor switch on radiator, did not help. My friend says I should replace the relays and resistors. Are these the right parts:
resistsors:
http://www.ebay.com/itm/NEW-Auxiliar...ZXDQA8&vxp=mtr
relay:
http://www.bavauto.com/fland.asp?par...FYsmhgodRjEKmQ
and if so are there any good tutorials on how to install these?
Thanks and sorry if this has already been covered, but I have searched for a couple of hours now to no avail.
thanks for the reply. do you mean this: http://www.ebay.com/itm/New-AC-A-C-C...ZXLEmL&vxp=mtr
Dude, this... but NOT for this price!
Something wrong with their heads!
Try places like: AutohausAZ.com, PelicanParts.com or ECStuning.com.
Whatever works better for you and search for P/N 64548380780
Top price you will find for Genuine BMW is $560.
I got mine for $163
BMW CCA 434493
thanks for the advice siny. So I jumpered the aux fan so that it runs on high all the time to eliminate that as a source for the overheating. I replaced both thermostats. I have taken it on some ~2 mile rides getting up to 50mph, it has not released any steam from the expansion tank since I jumpered the fan and the temp gauge is not going above half, but it still makes pinging noises when I shut it off, and the big hose on the bottom right (left when looking in from the hood) is not getting hot while the hose on the top left (right when looking in from the hood) is getting really hot. A mechanic with a 540 said that I need to take it to the dealership, pay 200 for a diagnosis, and then $80 for them to bleed the coolant system properly with special equipment even if nothing else is broken.
So I'm wondering:
1. Has anyone else heard that you have to go to the dealer to get a proper bleed?
2. Why is the temp gauge not going above half, but the engine is making pinging noises upon shutoff?
3. Why is the bottom hose cool even after I replaced the thermostat?
4. Should I just replace the whole cooling system myself?
Last edited by thesniffingratt; 06-18-2016 at 03:24 PM.
1.You jump AUX fan to see if its motor operational. If it operates at HIGH then there is problem with your relays or MOST LIKELY resistors.
Instead of hassle with just resistors replace WHOLE A/C Condenser (AUX) Fan Assembly!
2.Did you replace Thermostats yourself OR had them replaced? Because I thought we have only 1 Thermostat. At least on my car...
3.You do NOT need Special Equipment to bleed your Cooling System and you can do it for FREE.
BMW CCA 434493
Hi Siny, thanks for the help, yes I will do that whole aux fan assembly, although I already did the temp switch for it, and the relays, but it will still only run when jumpered on high.
I didn't seem right to me that you would have to go to the deal just to bleed the coolant system, so I guess I should just go ahead and rebuild the whole cooling system?
Jumpering the AUX Fan at the Temp Switch is just a TEST, showing that your AUX Fan motor is OK, but your Resistors are NOT.
For Bleeding and Overhaul the Cooling System you gotta read following topics:
Cooling System Bleeding
ENTIRE COOLING SYSTEM REPLACEMENT Tips and Tricks (Very Long, Enjoy!)
Enjoy!
Hope this will help!
BMW CCA 434493
I am late to this party (this thread was started 10 years ago, in 2006!).
Anyway, my Aux Fan is screeching, so time to replace it.
If you want to replace only the motor, then it is now Four Seasons 75720 (bought on ebay for $60).
If you don't want to deal with the wiring and heat shrink tubing, buy a new Aux Fan Assembly.
1. Tools are: 8mm socket, 10mm socket and 13mm socket.
- Torx 50 (not Torx 45).
2. Heat shrink tubing.
2. Watch youtube video on how to remove bumper by bimmermerchant.
3. READ the DIY by daw on bimmerfest.
4. Once the bumper if out, removing the Aux Fan assembly is straightforward (10-mm nuts).
5. Installing the new motor is a bit tricky. WATCH carefully the factory setup, then reproduce it.
- Basically routing the wires properly.
- In the connector: push the Brown and Black-Blue wire out of the connector (push them out).
- Make sure you mark which is which, when in doubt, look at the other side of the connector for the Brown Wire etc.
- For the Black-Blue wire: cut it and use a butt connector, don't solder it. Slide the heat-shrink tubing in first!
- Then use small amount of heat to shrink the tubing, don't burn the wire!
- Note the tab on the triangular piece and how it faces the C-Clip.
That is all folks. A few photos for those who need them...
E39-AuxFan-01.JPG
E39-AuxFan-02.JPG
E39-AuxFan-03.JPG
Hey guys, for the reference of future readers, just in case you change cars, could you note whether your car was 98 or older, or 99 or newer?
The fans are different. Jumping power to the newer, PWM controlled fan on the 99+ cars is NOT a valid test, and depending where you connect power, you could fry an otherwise good fan.
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