Aux fan gone south, looking for dimensions for aftermarket

[beetos]

Well some pretty scary **** happened to me the other day. I recharged my completely flat battery the WRONG WAY and when I hooked it up, it caused all kinds of problems (revserse charged). Not sure I remember hooking up the charger the wrong way, but when I had it checked they told me it was revered charged!! It was dark when I put it outside on the patio so I don't doubt I must have f'd up.

Luckily though, I did not fry anything apart from my aux fan. Either that or it was on its way out anyway. For a while I thought I killed everything including my Haltech stand alone but I was very lucky.

Anyway, I was wondering if anyone knew the diameter and thickness of the factory aux fan so I could look into getting an aftermarket fan. I am already running a davies craig 16" puller instead of the viscous fan on the inside and like it. Was wanting to put one on the other side for the ac condenser.

Cheers.

[MBXB]

Someone on this forum installed an aftermarket that fit right in. I think it was a Flexalite. Search the archives.
I'm curious how you installed your puller and how you wired it.
How bout some pics on that?

[Gearhead]

Funny, my aux fan isn't working either. No overheating whatsoever, but the A/C doesn't work well until the engine warms enough for the clutch fan to start pulling air.

I'm still not sure if it's the fan, or relays etc. Something I have to troubleshoot this weekend. But I did find something interesting on the Realoem site that I'm hoping could be the issue rather than a dead fan.

http://realoem.com/bmw/showparts.do?...32&hg=64&fg=55

Notice item number 6 describes a "repair kit resistor". Beetos, do you think maybe you wiped out the fan resistor with your battery fiasco? Does anyone else have experience with these fan resistors? Man, I'd sure rather drop $45 on this rather than replace that fan.

Oh and btw... how the hell do you get to it if you have to yank it anyway?!? The bentley manual goes over troubleshooting lightly, but mentions nothing on R&R. I'm guessing you'd have to yank the grille and the air dam underneath the bumper and pull it down/out that way. Who's done this before?

Thanks all!

John

[mikell]

4 possibilities that I can think of: The fan is kaput; the resistor is kaput; the relays (or one of the two) died; or the temp sensor has gone tango uniform. The Bently manual has a trouble shoot in it. Most often, it's the resistor, which is replaceable and not too expensive - but, if that's your problem, the aux fan will still work on high speed, so you could just jumper around the resistor, I guess.

[beetos]

Cheers chaps. Everything is verified working other than the fan. Have probed the connector at the fan which shows 12v on both the resistor (slow) and the 'fast' wire. Fan shows open resistance so if definately f'd. I understand the best way to get at it is to pull the bumper.

[winfred]

pulling the bumper is the only easy way

Cheers chaps. Everything is verified working other than the fan. Have probed the connector at the fan which shows 12v on both the resistor (slow) and the 'fast' wire. Fan shows open resistance so if definately f'd. I understand the best way to get at it is to pull the bumper.

[Gearhead]

Beetos,

Well at least you now know what the issue is. Dealing with my fan battle, I found much the same thing. Actually found that the fan motor is indeed working, it's just the fastener which couples the fan blade with the shaft is missing, so the motor is freewheeling. The shaft out of the motor is rather chewed up as well. I really don't think a new fastnener would work because of that. Sure would like to have a mig welder about now...

Anyway, to find this out i had to remove the front bumper. When I saw posts stating this was "easy" I was very skeptical. But it really is. Here's a site that helped me greatly.

http://home.comcast.net/%7Ewinstonfo...illremoval.htm

The trickiest part is figuring out how to remove the plastic trim off the bumper to access the four mounting bolts. For this, I relied on a diagram from realoem.com
http://realoem.com/bmw/showparts.do?...10&hg=51&fg=15
Basically, looked at the locations of the little plastic tabs that you must depress. I used a thin and wide flat-blade screwdriver. The one in my leatherman actually worked better than anything in my toolbox. Work the tabs starting from the front where they end at the center piece and work your way out toward the corner. Once you get to the corner, you don't have any more tabs to deal with, you just simply pull the trim "forward" toward you. The sides of the trim are attached via slots and molded "hooks." If you don't realize this, you will likely break these plastic "hooks" as I almost did.

Once the trim is off, it's a matter of four nuts and slowly lowering the bumper. Before you can set it all the way down, you'll have to disconnect your fog lights, remove the exterior temperature sensor and side marker light sockets. That's it.

Now, the grille is a different story. I spent about 20 minutes messing around with the outermost clips shown in the 3rd image of the first link I provided above. With the bumper off, you can reach your hand up from underneath and press it down with your fingers. I know I was fully depressing that thing, but for some reason it feels like there's another clip or something else attaching it at the end where it mates with the fender. I couldn't figure it out as it started getting dark and I had to put it all back together. I'll save that battle for another day when the replacement fan comes in.

I hope this helps.

John

[Ross]

Just changed mine at the same time as my w-pump. If you remove the rad hoses and fan it's easy to lean the rad in to remove the aux. fan.
Not a bad time to think about the pump then.

[beetos]

John
Great info, a big help. Thanks a lot.