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!
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.
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!
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 !!
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!
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.
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.
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!
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!
Hidden modifications just add to the confusion OP,
Uturn just brought it to light, thanks UT540!
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!
IMG_0527.JPGAlso 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!
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!
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
Thanks for the clarification Jim!
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
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!
I see,
well then, what does that leave to consider,
as to the cause of fuse #7 blown?
OK,
#1.#2.It appears you may have blown the IHKA panel depending on where you pulled the power for the toggle switch.Sorry to be so blunt, but you're insisting!If F7 blows, the relay coil, or the IHKA panel, is bad. Not a good idea to install bigger fuses.
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.
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