Aux fan crapped out on me

Driving down a 4 lane highway with no problems with A/C on in 88 degree weather Come to traffic that is stopped completely After sitting for a few minutes, I look down to see the temp needle climbing ever so slightly CRAP !!! I turn the A/C off and it still creeps upwards I turn the car off. Get heat soak to about the ¾ mark Not sure if to try to crank it and slightly rev the engine to let the fan clutch do it's job. Dediced to just watch it, leave the car off and make sure it doesn't climb above 3/4. Traffic begins to move and the temp comes down to the ½ mark like usual

So, I did a complete coolant system overhaul about 40-50K miles ago, so I’m pretty sure it’s not anything assocoated with those parts. I crank the car, turn on the A/C and check the auxiliary fan and ….. yep …. you guessed it. It’s not turning. Check the fuse …. yep ….. it’s blown. Next, check the aux fan and ….. yep ….. it’s very hard to turn by hand. CRAP !!!! .....Didn’t even bother replacing the fuse. Same thing happened to my previous E34, but the tranny let go before I got around to replacing the aux fan.

Ordered a Seimens replacement aux fan from AutoHausAz for $154 with free shipping

I hope to put it in next Sunday. I will not be driving the car in the meantime as I will be on vacation starting Saturday and will not need the car.

Now, who here has replaced one? I have looked at a couple of DIY’s and it doesn’t seem that hard. Any words of advice from those who have replaced their aux fan?
.

I would be more concerned with the condition of fan clutch. The aux fan is a pretty big repair half day at least. I look for the diy link i had. At least you saved it . Im pretty sure you have to get to it this way .http://home.comcast.net/~winstonfong...illremoval.htm. Best wishes lD

I did mine last summer and it took me like 30 mins to do.

Easiest way is to remove the license plate then remove that piece behind it then its ease from there.
I would suggest replacing the resistor also as it might have gone bad too.

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Originally Posted by luckydog

I would be more concerned with the condition of fan clutch. The aux fan is a pretty big repair half day at least. I look for the diy link i had. At least you saved it . Im pretty sure you have to get to it this way .http://home.comcast.net/~winstonfong...illremoval.htm. Best wishes lD

The fan clutch is fine. I checked it too, I just didn't include that in the write up. It spins with the very same resistance it did when I got it new in Nov 2011.

Originally Posted by generalea

I did mine last summer and it took me like 30 mins to do.

Easiest way is to remove the license plate then remove that piece behind it then its ease from there.
I would suggest replacing the resistor also as it might have gone bad too.

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I'm pretty much of an electrical moron. What exactly does the resistor do in relation to the fan clutch?

Sorry, I meant that for the electric fan and not the fan clutch.

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I'm confused on how the electric fan (auxiliary fan ) could be removed in 30 min via the removal of the plate frame . Could you please elaborate more . Thanks

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Originally Posted by generalea

Sorry, I meant that for the electric fan and not the fan clutch.

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Nope ... my mistake. I meant to ask what does the resistor have to do witth the aux fan?

Originally Posted by supertech777

I'm confused on how the electric fan (auxiliary fan ) could be removed in 30 min via the removal of the plate frame . Could you please elaborate more . Thanks

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+1, i was confused by this also

In that web link it shows that they are removing the entire bumper
When I did mine all I did was removed the plate and bracket and the grill.

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Ok got it , thanks

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Sorry for my ignorance, but at what temp/condition is the Aux fan supposed to come on and can you hear it running from inside the cabin?

Originally Posted by Tims_535

Sorry for my ignorance, but at what temp/condition is the Aux fan supposed to come on and can you hear it running from inside the cabin?

Typically the low speed at the 12 gauge position and high speed at the 3/4 position.
You can test the resistor and aux fan speeds via Bentley Test - jump the electrical connector to the temp sensor on the upper passenger side of the radiator with a paper clip. I doubt you will hear it from the cabin. I certainly don't. It should also come on with the AC switch.

The resistor is a black small rectangular box located on the grill side of the aux fan about midway up. To replace you have to clip the wires and reattach. I bought a cheap one off of ebay from an electrical supply store - sorry couldn't find the link. Still works - but my car does not move much. Not sure if I would replace the resistor just to replace it. Because it is electrical it could last forever or never


http://www.nmia.com/~dgnrg/page_20.htm

Originally Posted by luckydog

I would be more concerned with the condition of fan clutch. The aux fan is a pretty big repair half day at least. I look for the diy link i had. At least you saved it . Im pretty sure you have to get to it this way .http://home.comcast.net/~winstonfong...illremoval.htm. Best wishes lD

You don't need to remove grill AFAIK, its a very easy repair from radiator end.