Official Electric Fan wiring thread!

[325e10]

Thanks. what do i use for the 2pin connector/harness to the fan .just replace existing3 pin with some 2 pin ?
sorry kind of losing it here :?

That is stated in the OP but

after the 3 pin connector for the fan. The brown wire is ground. The Black wire is low speed (if you want AC you need to hook this up) and the Red wire is High speed (what the temp switch will kick on).

So Brown (from the car) goes to the ground wire on the fan while red and black wire(from the car) go to the power wire on the fan. Only one wire sends energy at a time. Never both.

[nando]

I ran the exact same setup, stock 89' 3 pole sensor and 80C T-stat and while driving holds at 1/2mark, and fan comes on at 2/3

either you have the wrong thermoswitch or you have it wired backwards.

[bzboardz]

I run the 80/88 3 pole sensor, and the fan kicks on low speed at about 2/3 up the gauge...seems a little off? I run the 80C T-stat and my temp while driving holds between 1/3 and 1/2 marks. If I sit in traffic, the temp creeps up above half and, as stated above, the fan doesn't start up until the upper 2/3 area. Is that what you guys with the 80/88 Are experiencing?

Seems wrong to me....maybe they accidentally gave me a 91/99 switch? Can anyone vouch for the approximate temp at the 2/3 mark? My fan is an aftermarket SPAL and the wiring is good to go, just not working in the expected regime.

I ran the exact same setup, stock 89' 3 pole sensor and 80C T-stat and while driving holds at 1/2mark, and fan comes on at 2/3

[36brua]

yes replace the 3 pin switch with the 2 pin switch.

Thanks. what do i use for the 2pin connector/harness to the fan .just replace existing3 pin with some 2 pin ?
sorry kind of losing it here :?

[325e10]

I always just utilize high speed and use this switch: (61-31-1-364-272..
ok I give up. Where is this switch is installed ? replaces temp switch in side of radiator? and if in radiator my connector is 3pin 89 E30
thank you

yes replace the 3 pin switch with the 2 pin switch.

[36brua]

I always just utilize high speed and use this switch: (61-31-1-364-272..
ok I give up. Where is this switch is installed ? replaces temp switch in side of radiator? and if in radiator my connector is 3pin 89 E30
thank you

[328ijunkie]

Glad to see people still mostly referencing this thread vs making new ones lol. ;)

[eurosport22]

i hooked mine up so that high speed is the one that always comes on. i also used the 82 degree fan switch.

http://www.rmeuropean.com/Part-Number/Auxiliary-Fan-Switch-2-Prong-(White-Top)-82-deg-C-__6131136427282_FAE_10832E0B.aspx

i dont know where my resistor went but if it doesnt run very long then it shouldnt make a difference. i used a spal 16" pusher wired up like in the first page and it works perfect. the only thing is i had a factory 15amp fuse in the box so when i hit the switch it poped right away. threw a 30 amp in there and boom. perfect.
http://thmotorsports.com/spal/spal_f.../i-520006.aspx
its a little pricey but it moves over 2,000 cfm's and its gets to the mid to high 90's here in md over the summer so i figured id be safer than sorry

[singh336]

awesome, thanks!

[Lithium]

What aux fan is best to use for space / CFM , i don't care about noise really, just want something for a good price.


I searched for the fan switch you for, found it for 8.99, should I be searching for that under my E30, or for an E36/E34 for the M50 motor?

Where does this thread into and does it directly fit or need to be rethreaded because I thought one of these temp sensors needed to be rethreaded?

82 deg fan switch is from a 1984 318i - it screws right into the rad no worries.
I am using the stock fan - there are allot of aftermarket options & opinions to match - but for 33$ Ireland Engineering has a 14" fan that should do the job.
PM me if you need any more info.
ChrZ!

[singh336]

I just hooked up the 82 Deg fan switch that I got from http://www.bimmerspecialist.com - It was under 10 Bucks - I connected the two wires from the high speed and that was it - It works perfectly - Comes on when it hits 82 exactly and only runs for about 30-45 seconds and the motor cools right down.
Great Mod - Great Thread - Most helpful > THANKS!!!!

PS: I am using the stock fan with AC deleted.

What aux fan is best to use for space / CFM , i don't care about noise really, just want something for a good price.


I searched for the fan switch you for, found it for 8.99, should I be searching for that under my E30, or for an E36/E34 for the M50 motor?

Where does this thread into and does it directly fit or need to be rethreaded because I thought one of these temp sensors needed to be rethreaded?

[Fusion]

Guys, if the two top wires on the °o° radiator switch get flipped, will the fan speed be fast then slow?
I ask because I had to fix the wires there that broke off and now I think I heard the fast speed come on first, which leads me to think I might have flipped them. They were both yellow, iirc, one y/brown, the other y/purple.

[Lithium]

Sweet!!!!!

I just hooked up the 82 Deg fan switch that I got from http://www.bimmerspecialist.com - It was under 10 Bucks - I connected the two wires from the high speed and that was it - It works perfectly - Comes on when it hits 82 exactly and only runs for about 30-45 seconds and the motor cools right down.
Great Mod - Great Thread - Most helpful > THANKS!!!!

PS: I am using the stock fan with AC deleted.

[NERDE30]

I got a question for you guys . I can not seem to figure out which 80deg thermostat to us with my S50 . Can anyone point me in the right direction ?

[bstarr3]

Sorry for the dumb question, but what additional wiring, relays, connectors etc do I need to wire a fan exactly as described in post #1? I know nothing about wiring, automotive or otherwise. Am I running wires from the temp switch and from the aux fan harness into the new fan? My new fan only has two wires and a plug connector. Thanks fit helping a noob

Sent from my DROID RAZR using Tapatalk 2