Official Electric Fan wiring thread!

[Highway1]

Ok well I tried pushing the snowflake button again and the fan turned on for about 15 seconds. then it cut out. After it cut out i noticed a relay clicking on-off about every 5 seconds. i traced the sound under the dash and found the A/C relay. is that clicking normal? bad relay? shorting out?

[328ijunkie]

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?

Try jumpering different pins. It kinda seems like your fan resistor is blown. Check all fuses.

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...?

i have no idea what kit/module youre using so i cant tell you much as far as whats going on with it. Can you post up the diagram they included in the kit?

Ok well I tried pushing the snowflake button again and the fan turned on for about 15 seconds. then it cut out. After it cut out i noticed a relay clicking on-off about every 5 seconds. i traced the sound under the dash and found the A/C relay. is that clicking normal? bad relay? shorting out?

AC switch may be going bad from the sound of that. Or poss that relay but i would keep investigating why high speed (non snowflake speed) doesnt work.

[Highway1]

Thanks 328ijunkie, i'll check out the relay. i know it's not my resistor because i wired the fan up to 12v directly and both low and high speed work. also the snowflake stays illuminated while the relay makes that sound

... Or I may just wire up my own relay directly to the temp switch and bypass the whole a/c system entirely.

[328ijunkie]

Or you could wire it the way i posted so you dont have to mess with any of that ;)

[Highway1]

I bypassed the diode and now the low speed comes on when i press snowflake when i jump blk to blk/brown it activates high speed. however when snowflake is NOT on, jumping the three prong plug does nothing.... i'm confused.. is it safe to run without the diode or is that why jumping the plug doesn't work?

[328ijunkie]

Does the relay fire?

[Highway1]

Nope. Only when snowflake is on, which is useless to me. I'm going to try a working diode and see what happens.

Edit: I thought I checked all my fuses... and I had checked all the fuses. The problem was one was missing. doh!

[328ijunkie]

Glad you got it figured out :d

[gkurey]

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.

[Highway1]

It should come on just before the halfway mark

Does your Spal fan have two speeds built in? Most after market fans do not. It sounds like you have the high speed (88°) wire hooked up to the fan. Try switching to the other wire.

[328ijunkie]

On all my 82 single pole sensor cars it comes on a tick over half.

[748Snowman]

+1 for sticky

[gkurey]

I will investigate and let you all know, thanks for the input!

[SHunter]

What's the point of running the engine so cool? All the fuel and timing maps are based on a 92C engine not an 80C engine. In OBD2 an 80C thermo should cause a CEL and keep the engine in open loop all the time, killing gas mileage and losing power over most of the rpm range. Am I totally wrong here? For OBD1 you might not get a CEL but it won't run as well. It seems like you'd only want to do this on a track car that is only run at WOT all the time.

A simpler solution to all this would just be to run the factory switch, thermo, resistor, wiring, etc and not worry about changing around the whole system. Is there a big benefit to doing this that I'm not seeing?

-Steven

[328ijunkie]

Well ill chime in about this since i made the thread i guess.

Not 100% sure about OBD1 but the OBD2 ECU triggers closed loop at 165F. So using an 80C thermo is plenty fine. The ECU also Knows exactly what temp its at so it adjusts fuel trims and stuff accordingly. Yes it is always better to run an engine as hot as possible to get the most efficiency/power out of it, thus why BMW now uses 99+C thermo's in newer cars. But the biggest problem with that is no buffer when a failure occurs. Thus you have all these M52TUs/M54s and up pulling head bolt threads and stuff like that because the second they do start to run hotter than designed its already too late, in addition to the fatigue it puts on the aluminum running it that hot all the time and heat cycling it at those temps.

The biggest problem is how prone to issues these cooling systems are. Fan clutches failing, Hoses failing, WPs failing, etc and if running the factory setup you have no buffer to keep the motor from exploding if you do have an issue. Yes you would get marginally better MPG/power running it hotter but i prefer to keep it safer and prolong the life of the motor.