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Jul 31, 2008 | 09:43 PM

#26

katanabob

Neutral

Joined: Nov 2007

Posts: 10

Likes: 0

Quote:

Originally Posted by Niko

Does anyone know where the high and low speed fan relays are located? All I see is one relay in this diagram.

http://www.realoem.com/bmw/showparts...20&hg=17&fg=05

I'd like to test the relays as a last resort before replacing the entire cooling fan assembly.

My '02 MCS has two plugs coming from the fan. (So does the above linked picture on realOEM.com, if you look closely)

The smaller of the two plugs has two small wires that go to a relay resident inside the 'black box' of the fan housing. (This relay receives signal power via a 5A fuse in the engine fuse box. If that fuse is blown, you will inhibit operation of that relay.)

The larger, three-wire plug has a hot wire (switched by the above mentioned relay), a ground, and a switched power that comes from one of the relays in the engine fuse box.

Last edited by katanabob; Jul 31, 2008 at 09:46 PM. Reason: clarification

Aug 6, 2008 | 10:53 AM

#27

cycleway4

2nd Gear

Joined: Feb 2008

Posts: 96

Likes: 0

Quote:

Originally Posted by katanabob

The resistor is relatively easy to find/replace. (It's a 0.32 ohm wirewound resistor.) It's wired in series with a thermal cutoff (Thermtrol DF184S) that's a pain to solder around. (Be sure to use pliers or something as a heatsink downline when soldering near it.)

Are you saying that replacing this resistor fixes the problem of no low speed for those that have that symptom?

Resistor probably available from RadioShack?

Steve

Aug 7, 2008 | 04:45 PM

#28

volki

4th Gear

Joined: Jun 2006

Posts: 303

Likes: 5

Since getting a new power steering fan about 2 months ago, the "behavior" of the cooling fan changed completely. It used to come on "full speed" after circling the parking structure for 5 minutes or driving a bit spiritedly. Now it works at low speed constantly when the AC on, and comes on ONLY after sitting in traffic for long times, etc.

I dont know what to make of this, but it appears that my old PS fan was not working properly and the cooling fan was on lot more often because of this???