Aux/AC Fan replacement

[PorkandBeans]

My aux/AC condenser fan is not working. I searched and found lots of useful info, did some troubleshooting, and found that it's in fact a bad fan that needs replacing.

My question: Is there a way to replace this fan without draining the cooling system and removing the radiator (as the Bentley says)? This is a stock set-up on a 85 325e.

My A/C is just cold enough to be acceptable when at cruising speeds but is cool (not cold) when in stop and go traffic. I'm hoping the aux fan will help keep me from an A/C service. I don't know if it's been converted yet and have to take it to a shop for the evac, vacuum test, and recharge.

Thanks in advance

[dude8383]

You can remove the front valance.

I'm actually going to do this over the weekend.

[PorkandBeans]

I just finished. I didn't have to completely remove the valance though. I took off the trim below it and removed just enough screws to move the metal valance out of the way and slip the fan out. I had to remove the passenger side plastic grill trim (around the lights) to get at one of the fan mounting screws. This was much easier than removing the radiator would've been, thanks.

I think this has done the trick. The fan has improved the coldness of my A/C around town and my temp gauge never goes past 12 o'clock when parked with the A/C on in some pretty nasty heat & humidity. I don't think I'll need to service the A/C at this time. Spending that money on a tint now...

[PorkandBeans]

Crap. I let my dad borrow the car yesterday and when he returned it the aux fan was inoperable. It was 97 degrees and knowing him it was probably parked with the A/C on high while he made phone calls. I don't know if that's what did it but... Anyway, I checked fuses 3, 18, 19, & 20 and #18 (30 amp) was blown. I replaced the fuse but still no fan. I swapped out the two relays, no change. Any ideas? I'm was going to apply direct power to the fan to make sure it still works but I'm assuming I didn't burn it up in 1 day. The thermo switches at the radiator and the resistor on the fan shouldn't cause the fan to not turn on if the A/C button is depressed, correct?

[PorkandBeans]

Aux Fan Help Please

The fan does not turn on when the A/C button is depressed. It does not turn on if I jump the low speed thermo switch at the radiator. It does turn on (hi speed I assume) when the high speed thermo switch is closed. This leads me to believe it's the resistor. It's a difficult part to find.

Siemens .5 Ohm 85W DALE 353-002-01. Anyone have a source for this that is reasonably priced?

Actually, I would prefer to just have the high speed on when the A/C is on. Anyone know how to remove the resistor and wire the aux fan to use high speed at all times? Is it as simple as just removing the resistor? I'm a noob when it comes to electrics but I did buy a voltmeter for troubleshooting and am learning as I go here.:)

[dude8383]

http://www.bmaparts.com/item.wws?sku=BSH018136&itempk=71864&mfr=Bosch&weight=0.12

http://www.bmaparts.com/item.wws?sku=BMW068193&itempk=121360&mfr=Aftermarket&weight=0.12

:D

[PorkandBeans]

I jumped the resistor and put a 30 amp fuse in slot 3 (was 15 amp). Now when the A/C button is depressed the fan is always on high. A/C works much better now and blows cold.

[bmwstephen]

bump, Pork and Beans, do you have any pictures of your jumped resistor set up?

[PorkandBeans]

The resistor has two wires on it, one on each end. I just cut these and spliced the wires together. Simple. I left the resistor on but it's just sitting there not doing anything. Now when the fan gets the signal for the low speed to turn on it still gets full power and runs on high. This is why I swapped a bigger fuse for the low speed fan.

[bmwstephen]

I see thanks! one more question though since I'm not really electronically compitent...

when I do splice the wires together, how does the fuse impact the way the fan operates from here on out?

[PorkandBeans]

Without the resistor restricting amps for the low speed, you would blow the 15 amp fuse. Basically you're converting the low speed fan into another high speed.

At least this is the way I understand it. I got this idea from someone on another thread when I was trying to source a new resistor. I posted it because it's a much better way to solve the problem; it's cheaper, requires no parts, and it helps my old ass A/C stay a little cooler by running the fan at high speed at all times.

[txtorquemade]

Damn nice idea Skippy. Problem is Im not sure my aux fan is even coming on.