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Discussion Starter #1
I'm new here so sorry if i do anything wrong but i don't seem to find much on this problem.

E46 320i manual with only one fan.

Anyways my problem is that my electric cooling fan does not turn on when the car gets to hot, like ideling. And I have replaced the temp sensor on the lower hose. So i was about to buy a universal fan and a simple thermal switch but when i unplug the stock fan, the AC shuts of. Is there any solutions to this or should i put another fan infront of the cooler?

Thanks for anwsers!
 

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Sounds like you need to replace the fan itself. There's a relay in the fan unit that goes bad. You need it working properly for those times you do idle. I got one from fcp euro for $120 or so...worked fine. Don't 'hack' your cooling system...you want it working as it should.
 

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Do you think it can be the little box on top of the cooler? I find it wasteful to buy a new fan for that much money when i can get a universal fan for 40 bucks that's better than stock. But also the fan itself works, its just not turning on to temperature only ac.
 

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Is the factory fan or a very good OEM fan expensive, yes. But they last a very long time.
Are you aware that the fan has almost infinite speed control?
It's NOT an on or off.

 

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Is the factory fan or a very good OEM fan expensive, yes. But they last a very long time.
Are you aware that the fan has almost infinite speed control?
It's NOT an on or off.

Yes its nice it has variable speed as supposed to universal fan but right now its not very variable because its not moving. And i dont know if a new fan will fix the issue because my fan is working, it just wont turn on when the car is hot.

I will go to a junkyard soon and buy one of the little boxes that sits on top of the fan but if that doesn't work i dont think a new fan will either.

Thanks for the answers btw!
 

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Do you think it can be the little box on top of the cooler? I find it wasteful to buy a new fan for that much money when i can get a universal fan for 40 bucks that's better than stock. But also the fan itself works, its just not turning on to temperature only ac.
That little box has nothing to do with the fan. It’s actually an air pollution sensor. Search this forum for a thread on the electric fan in which BMW North has commented. He has a post on how the fan works.
 

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Discussion Starter #7
That little box has nothing to do with the fan. It’s actually an air pollution sensor. Search this forum for a thread on the electric fan in which BMW North has commented. He has a post on how the fan works.
Ok, thanks, but i just cut the cables from the fan box to the fan and have the fan box connected and hidden so i can install a aftermarket fan
 

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2004 330Ci 85k miles
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i just cut the cables from the fan box to the fan and have the fan box connected and hidden so i can install a aftermarket fan
That is a big mistake! You need the correct fan in there or your engine will overheat and blow the head gasket.
The factory electric fan not working at all speeds is a common failure on E46 and usually caused by a failed fan control unit, the metal box mounted on the fan housing that controls the fan speed.
Read this document to understand how it works.
 

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Discussion Starter #9
I have now successfully installed a aftermarket fan and temperature sensor and its working great and the fan doesn't impede air flow as much as the stock fan

But thanks anyways guys!
 

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2003 330cic, 2003 325iT
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That is a big mistake! You need the correct fan in there or your engine will overheat and blow the head gasket.
The factory electric fan not working at all speeds is a common failure on E46 and usually caused by a failed fan control unit, the metal box mounted on the fan housing that controls the fan speed.
Read this document to understand how it works.
He wasn't interested in fixing his fan. He liked the idea of a cheaper hack. All good - his car!

Too bad, I would have sold him a replacement AUC sensor ;)
 
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