Official Electric Fan wiring thread!

[Josh1254]

Ninja Edit...
Its rare but possible both low speed circuts are bad or theres the other possibility of you having the wiring flipped for low/high speed as the plugs like to turn to dust over time and youre seeing low speed fire but never seeing high speed fire....

Well, when the temp switch hits 88c the high speed fan turns on. When I hit the AC button inside the low speed fan turns on. So the wiring has to be correct.

If the low resistor is bad, it wouldn't work at all right? But mine does with the ac button and jumping the wires at the temp sensor plug.

Maybe both temp sensors I have are bad?

[indecline]

Sub'd for reference.

[328ijunkie]

Ninja Edit...
Its rare but possible both low speed circuts are bad or theres the other possibility of you having the wiring flipped for low/high speed as the plugs like to turn to dust over time and youre seeing low speed fire but never seeing high speed fire....

[Josh1254]

Alright guys, I read through everything and can't figure out my problem.

Its a 91 318is with a 95 318ti electric fan and 80-88c temp switch. I have all the oem wiring. The high speed fan kicks on when the temp switch is at 88c. I used a temp gun to check. The low speed does NOT turn on when the switch is at 80c. I tried two different switches too. Also, the low speed fan does turn on when I hit the AC button inside. When I unplug the wiring at the temp switch I can jump the high and low speed and both work great.

My only thinking is the low side of both temp switches I tried are bad?

Any other ideas?

[MrGreen]

Works perfectly! Used 61-31-1-364-272-82 with e30 Radiator with Spal pusher infront of AC Condensor for my M52 swap. Fan turns itself on and off great; turns on at about the midway point on the guage, cools the engine down and never goes much further than half on the guage. Then turns off. It also turns on when I turn the AC on. Very nice! Thanks for posting this!

[econti]

Can someone help me out here?
I'm awful with wiring, and am considering going to an electric fan instead of the mechanical driven one.
Car is a 91 318iS.

What do I need? Obviously a fan, do I need a temperature sender unit? How do I wire it all up?
I've read the OP many times and have read half the thread, but it just doesn't make sense to me.

[bmk]

So I gonna be running a Volvo fan with integrated 2 speed relay as pictured.

I am running a stock e36 radiator with what I think is a 90/98 3 pole Will this work if I wire it according to the above schematic? I plan on cutting the pig tail and hooking it up to fan 1 which is low speed and fan 2 which is high speed (The center two) on the volvo unit. However what are the prongs on the e36 sensor which one is low speed, high speed, and ground? And im assuming I hook the low to low and high speed to high speed and the the left over wire from the sensor is ground?

[318isbmw]

ETA fan switch wiring is on the drivers side....

Gotcha, thanks. That clears it up.

[328ijunkie]

ETA fan switch wiring is on the drivers side....

[318isbmw]

I'm starting to tackle the fan wiring project, but running into a few snags along the way. I'm not sure if it's just my understanding, or if I have an issue.

I have a 1986 325e which currentlyhas no electric fan installed, and the previous owner hacked up all of the wiring up near the right-hand headlight.

I've found the plug over on the drivers side with the green/black, blue/black, and brown wires. There is nothing on the end of that plug, but my understanding is that:

Grn/blk, blue/blk - > electric fan power
brown - > electric fan ground

Now, my issue comes into play on what wires go to the temp switch. On my passenger side headlight area, I don't have a blue/blk or a grn/blk wire. Is there something that I'm overlooking?

For reference, here's what my passenger side looks like. Previous owner took off the plugs on every single wire that wasn't being used, so I can't just identify what plug goes where.

[328ijunkie]

If youre trying to use both speeds then yes the 80/88. The only reason i prefer just having the fans immeaditly hit on high at 80 is because most (i havent run a volvo fan in a car personally) fans dont flow enough on low speed and the motor is cooking pretty good by the time the high speed hits...

And as far as wiring the volvo fan, run the stock main power wires to the fan relay and run power for the fan externally to the battery as the factory fan wiring will never support that many amps when high speed hits....

[bmk]

Has anyone used the a fan from the volvo v70, 850, or 960? Ive read they flow anywhere from 3000-3500 cfm and pull 17 amps on low speed and 35 amps.

JTR suggests that I use the bmw relays to trigger the volvo 2 speed relays, does anyone have input on how this would work?

This will not be in BMW swapped car but rather an LS swapped car if that helps.

Thanks

Simply have the power wires that went to
The stock fan fire the relays built into
The Volvo fan, then run fused power and ground to the fan relay

So since I want to use the low and high speed settings which temp switch do I need to get... The 80/88 3 pole?

Also when you say run the fused power and the ground to the fan relay are you referring to the stock bmw fan relay?

[Nick_S]

did you delete your ac or do you still have it?

regretfully I deleted it. Really should have kept it and tried to make it work.

[328ijunkie]

AC is make or break... Gotta have a killer fan if youre in the south and need engine cooling and AC :P

[Mistawall]

Yes but there are cheaper options out there. I use a Jegs straight blade 16" fan and since I moved to LA and commute through horrid downtown traffic, it has never once crept near the half way mark. Only downside is the straight blade fans are louder but it doesn't bother me.

http://www.jegs.com/i/JEGS-Performan...ductId=1042833

did you delete your ac or do you still have it?