Wiring aux fan to a switch!!

[e30 gangsta]

IS this how you should do it?

Unplug the plug that plugs into the radiator for the aux. fan. Late models its on the passenger side (next to headlights) and early models its on the driver's side (top of radiator almost). Just get a piece of wire and try to jump 2 of the pins in the plug. There should be 3 pins. 1 is for high speed. 1 is for low speed, and 1 is the ground. With trial and error you can figure out which pins are which. All I did was find which one was ground and low speed. Then from the ground run a wire into the cabin wherever you mount the switch. Hook it up to the switch, then run a wire from the switch back to the low speed pin on the plug. Then when the switch is "on" the fan should turn on low speed.

e30 gangsta wrote:
i have my ac still in the car. Also is there anyway possible to have a dual stage switch that has 3 positions. 1 low and 1 high and 1 off?


Yea, get a double pole switch. I think its STDP or whatever. Off would be the middle position, low and high would be either down or up. It would be the same only there would be a wire going from one pin on the switch to the low pin on the harness, and there would be a wire from the other 'on' pin on the switch to the high pin on the harness. I think that would be correct anyways.

What do yall think? thanks PeaveyBassist

[PeaveyBassist]

No problem. One thing I shoulda mentioned... The ghetto way to do it is to leave the plug still attached and just put the wires in the holes and wrap electrical tape around it. The "correct" way to do it would be to take the top of the plug (it clips in on the end where the wires come out) and figure out which wire is which, then crimp all the connections on.

Will

[ryan_george]

Are you removing the main fan bolted to the water pump? Is the aux fan alone sufficient for cooling?

[e30 gangsta]

i was gonna crimp em regardless. And i am using the ac fan along with the clutch fan i would not suggest taking off your clutch fan for everyday use. At least not in miami.

[clutterbucker]

So what if I lived in buffalo where it was never over 85 to speak of.....how would I wire it up without a clutch fan?

My new engine came with the fan delet mod already done, but my car isn't wired for it.

[trboblu74tii]

piece of cake.. make sure you run a fuse, and a relay.. just t-tap or solder your connections to the fan wires near the plug just behind the drivers high beam light. "triangle looking 3 prong connector.. there are two wires you can tap into blk is low speed and red is high speed and brown is ground.. i'm running the high speed with a relay and fused and using an extra fog light switch for fan control along with my fan delete mod..

[clutterbucker]

Is this using the AC fan? Or did you buy aftermarket. If so, what kind did you buy, or would I buy for a 1990 325i?

[PeaveyBassist]

piece of cake.. make sure you run a fuse, and a relay.. just t-tap or solder your connections to the fan wires near the plug just behind the drivers high beam light. "triangle looking 3 prong connector.. there are two wires you can tap into blk is low speed and red is high speed and brown is ground.. i'm running the high speed with a relay and fused and using an extra fog light switch for fan control along with my fan delete mod..

Why do you need a fuse or relay? Isnt there already BOTH of those for the fan?

Will