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525i winter driver
08-04-2008, 12:29 PM
so... long story short my aux fan isn't working at all. i know what i need to fix but i might not be able to get it going before going on a 2000km road trip this weekend (shoulda been doing that instead screwing with the hood huh?). my a/c is busted (ie i don't use it), radiator looks brand new and the temp gauge only rarely moves slightly off noon - never by more than the width of the needle. other than that the car is running great and i'm psyched to make this happen, this is the only thing holding me back from being very confident in this car. i've been stuck idling in traffic on a hot day and had no worries (believe me i was watching the gauge)... how bad do i need it?

Ross
08-04-2008, 02:21 PM
No worry. It's there mostly for the a/c anyway. As long as you are moving you could still run the a/c without it.
It does come on at high coolant temps w/o the a/c on but it you get into that territory the rest of the system isn't right.

Barney Paull-Edwards
08-04-2008, 02:43 PM
By the aux fan I assume you mean the electric one in front of the rad? If so relax,took mine off five years ago to get a larger intercooler in. be warned tho`, the gauge will not give you a good indication of over-heating until its too late due to its mounting position.

525i winter driver
08-04-2008, 05:53 PM
thanks a lot guys i was going to tear into my front end all over again tonight but i really don't want to - i'm feeling pretty good about the car now, (the A->B part at least) doesn't mean i won't keep my fingers crossed... better go vacuum the carpets, NY / New England here I come!

Tiger
08-04-2008, 08:59 PM
Aux fan is primarily for AC only... Secondary purpose is when engine are overheating.

shogun
08-04-2008, 09:26 PM
Aux fan failures either:
resistor
the 2 relays for high and low speed
magnets get lose in the fan motor (can be reglued).

Repair (German language) and pics
http://www.7-forum.com/forum/5/zusatzluefter-defekt-74182.html

525i winter driver
08-05-2008, 10:14 AM
Aux fan failures either:
resistor
the 2 relays for high and low speed
magnets get lose in the fan motor (can be reglued).

Repair (German language) and pics
http://www.7-forum.com/forum/5/zusatzluefter-defekt-74182.html
thanks everyone! in this case it looks like it's the switch/sensor at the radiator. when i jumper it as per bentley 170-4 the fan runs but it's hitting something and struggling a lot otherwise i would rig it to run on lo speed all the time.

weird thing - i look up the switch on real oem it gives me part#61311378073 but i can't find the part anywhere when i look for it for my car. pelican parts says the part corresponding to that number is for E36 325i/iC/is (through 8/95), 318i/is/iC, 318ti M42, M3 B30 (through 8/95)... i'm not sure what to order, i guess it's not urgent since my a/c doesn't work.

aux fan switch/sensor test as per bentley 170-4... jump the power leads to the (in my case brown always) ground and the fan ought to run when ignition is on.
http://www.bimmernut.com/forum/attachment.php?attachmentid=5813&d=1217948003

i should explain that's a homemade plug is why the colours are wrong and it looks funny... the real thing has all 3 terminals in a plug that actually fits. i made this one out of a washer pump plug and a good bit of a fried sword plug.... works!

http://www.bimmernut.com/forum/attachment.php?attachmentid=5814&d=1217948017