Official Electric Fan wiring thread!

[lolcantturn]

And who knows, it might actually be relatively cold that day and I might not need to use the fan at all.

[trackjunkie21]

you never actually need a fan, unless your sitting in traffic, at 55mph you are pulling in a lot of air.

[328ijunkie]

well after about 3 min of sitting still in the summer even if your not in traffic the temp will start to climb. If you DD the car at all you have to have a fan.

[NigelStu]

LOL, faulty brand new temp switch - talk about chasing your tail.

Thanks Dave and Erik for your help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Hum... I might have the same issue. Got the aux fan installed and wired in over the weekend, but it doesn't turn on.

Running the same 3-pole 80/88 switch as Giant.


If I unplug the switch and jumper the plug, both low speed and high speed fan speeds work. But nothing when plugged in. Let the car warm up so that needle was close to the tic-mark half-way between normal and the red zone.


Whats the best / proper way to test that switch so I can make sure it is actaully bad (although, I can't imagine it isn't)? Is there any other reason why it might not be working? Radiator has been bled properly, so I don't think there would be any air trapped near the sensor, thus giving false signal...



Also, with the temp switch plugged in, pressing the A/C(snowflake) button does NOT turn on the aux fan. Any ideas on that one?

[328ijunkie]

Thats weird that you guys are having these issues, only thing i can think is the pins are mixed up on the fan switch not completing the circuit like theyre supposed to.

[RoadHazard]

In order to test a switch, I'd dip the sensor part of the switch in water and boil it. As water temperature rises, use a thermometer to monitor the water temp. Connect an ohmmeter to the switch. When the switch becomes close circuit, read out the temp on the thermometer. Verify if that is what you're expecting.

[Hobbes]

Hum... I might have the same issue. Got the aux fan installed and wired in over the weekend, but it doesn't turn on.

Running the same 3-pole 80/88 switch as Giant.


If I unplug the switch and jumper the plug, both low speed and high speed fan speeds work. But nothing when plugged in. Let the car warm up so that needle was close to the tic-mark half-way between normal and the red zone.


Whats the best / proper way to test that switch so I can make sure it is actaully bad (although, I can't imagine it isn't)? Is there any other reason why it might not be working? Radiator has been bled properly, so I don't think there would be any air trapped near the sensor, thus giving false signal...



Also, with the temp switch plugged in, pressing the A/C(snowflake) button does NOT turn on the aux fan. Any ideas on that one?

There is a diode underneath the fuse box under the hood. It keeps your a/c compressor from kicking on when your temp switch turns the fan on. It usually doesn't go bad, but if it does, your fan won't run when you click the a/c button. It is also quite easy to blow up. (ask me how I know...) You can disconnect it and bypass it to see if it has gone bad.

That is a seperate issue from the fan not clicking on via the temp switch though. Is that side of the radiator hot when you are idling? My m42 radiator wouldnt trip the temp switch because it always had some amount of air, and it liked to settle up near where the temp switch is. If you think about it, it is probably the least turbulent part of the cooling system, and it also happens to be a perfect spot for air to collect. I noticed that changing to an aluminum radiator resulted in the temp switch reacting MUCH faster to change in temperature. Try jacking up the drivers side of the car (or park sideways on a really steep hill) and bleeding that way.

[328ijunkie]

^What he said. Thanks nick :D

[nando]

good to know about the diode, I know mine doesn't work with the button, and neither did the low speed. I bet the diode is bad..

[giantkeeper]

I bet that is why mine doesn't either. As a matter of fact I can likely pinpoint when mine went

[cbusrehab]

Are people running only 1 electric fan if you still have A/C? I'm in the process of hooking up the A/C and trying to decide if I should keep the AUX fan and add an electric puller or get rid of AUX and only use the electric fan. What are your thoughts?

[e30shmobberr]

What about if i am going to use the stock fan for the ac? how does that get wired

[328ijunkie]

Just wire in the fan switch i mentioned and reuse stock fan wiring. Should function as fractory would

[Highway1]

When I jumper the three prong plug on the pass side I get no fan. the fan tested out good and I swapped around my relays and still nothing. not even when i push the snowflake.
any ideas?

[devon.818]

i have the spal fan and spal kit from bimmerworld.
doesnt work! but i think its wired wrong:

atempt 1- red wire from module to (+) and yellow to (-) and the grey wire to the thermostat...
it is supposed to be hassle free, on and off by itself, but it wouldnt turn off without me pulling the fuse


so attempt 2- more of a fix to pulling the fuse. spliced in before the fuse and wired a AUX switch.


but in attempt 1, did i wire it wrong? bimmerworld and the spal directions said to do it tht way...?