Pusher fan

[Csaviano]

2001 X5 BMW 4.4

I purchased a pusher fan as my old one stopped working. I hooked It up and it still doesn't come on. Power to the fan is ok!

I noticed that the new fan has a metal box attached to it where the old one did not. Does anyone know if this box could be effecting it to come on or perhaps they shipped the wrong fan for my year and model?

[ants_oz]

The metal box is the speed controller electronics, which was built into the hub on the BMW genuine fan. I have an aftermarket one like yours and it works fine.

There could be other reasons the fan is nit activating, such as low pressure in the aircon gas. I believe there are also fuses to check.

[upallnight]

Stick with OEM

[Csaviano]

Got it. If I try to hook the fan on straight to a power source, I doensnt come on. Should it?

[ants_oz]

No it shouldn't. The fan has constant 12v power, and is triggered by a pulse wavelength which would be very difficult to reproduce.

there is plenty of info on the forum about this issue.

[g300d]

The fan has power all the time to it.

What turns on the fan is a PWM signal on the thinner third wire, from the DME.

You have to check for signal there, or hook it up to GT1.

AC working? One of the times you can make the DME turn on the fan is to put the AC on MAX.

EDiT: lol beat, yes, like ants said

[Csaviano]

can anyone tell me what the three relays are located under the passenger side airbag or behind the fuses in the glovebox?

[g300d]

Trader, yes, you're right.

Learned about all of that researching to diagnose my own failed fan lol.

I replaced it with a Behr from a local store, it's hecho en China.

Roars with less anger at full speed from how I remembered the OE fan, but OBD shows coolant temps same as with OE fan so I don't really think about it.

OE I pulled was a Siemens.

Yeah, wish these thing werent so whiz bang cutting edge when a simpler set up can do the job, but getting used to it lol.

[upallnight]

Originally Posted by g300d

Trader, yes, you're right.

Learned about all of that researching to diagnose my own failed fan lol.

I replaced it with a Behr from a local store, it's hecho en China.

Roars with less anger at full speed from how I remembered the OE fan, but OBD shows coolant temps same as with OE fan so I don't really think about it.

OE I pulled was a Siemens.

Yeah, wish these thing werent so whiz bang cutting edge when a simpler set up can do the job, but getting used to it lol.

But that's why you brought a BMW, for it Ultimate Driving Experience and it cutting edge design.

[upallnight]

Originally Posted by trader4

I wouldn't call putting a variable speed fan with electronics
in front of the radiator, in one of the worst possible environments
cutting edge design. I'd call it dumb. And it don't see how it relates to
the driving experience, except to cause more problems.

With a Pulse width modulated signal design, the fan has almost an infinite amount of speeds vs the old design where it was either low or high. A lot of energy is eaten up by the resistors use to control the fan speed, but with the pulse width, it uses less energy since no resistors are involved to control the fan. The fan is controlled by the amount of time it receives a signal from the DME. The faster the pulses the faster the fan will rotate.

This is the same technology that model railroaders use to make their trains run more realistically.