climate control , a/c

[Takimo]

mm well , ya i think i would start with the aux fan then... but have to wait for a couple of paycheck loll

[ants_oz]

Originally Posted by Takimo

is it possible that the ecu send a sginal to stop a/c when it detect a broken aux fan ?

The controller will not allow the AC to start of the aux fan is broken. Correct. One of the "startup tests" is to check whether the pusher fan is ok.

[Takimo]

whats the difference between pusher and aux fan ? im kind of confused, the part i need to purchase is the fan in front of the rad.. thats the aux fan right ?

[ndz]

http://bit.ly/1I1CXMC

[Alika808]

Originally Posted by Takimo

Because he told me i need to replace climate control which is around 1k...

What do your mechanic need to be replaced? Does he meant control panel? If so, the control panel cost less than $200.00.

[upallnight]

It depends on the failure mode of the Aux fan to determine if the AC compressor will still energize. For my aux fan failure mode it was a catastrophic failure of the control board.

See my post on my failure mode along with pic of the fan forensic analysis.

http://www.xoutpost.com/bmw-sav-foru...fan-fault.html

As a service to this community I think Trader4 should perform a forensic analysis of his bad aux fan and post pictures to this forum.

[StephenVA]

I think his Aux fan electronics is fried. The result in his case is the onboard thinks it is working or at least responding back that it is allowing the A/C compressor circuit to engage. As has been mentioned before, as soon as the fan is disconnected, the A/C electrical circuit will not send out a signal and the compressor clutch will not engage, due to no aux fan response....

In the good old days you would just jump 12V to the compressor to confirm its ability to function. Now days all parts up stream must be working before system tests will complete.

Bottom Line: Install Aux Fan (pusher Fan). It is ONE part not as the OEM image show. See bottom photo for example. I have use the Brand: Mahle-Behr with good results.

[upallnight]

Originally Posted by trader4

Why can't you still do this with the X5? Hook up 12V to the compressor,
take the car for a drive, which provides the necessary cooling for
the condenser. If it blows cold air, the system is working. Should
work, no?

This is just a test to see if the clutch engages and the system has the correct amount of refrigerant. You should not drive with the car set up like this since the system is designed to cycle off and on. With 12 volts jumped to the compressor, you eliminate the cycling of the system off and on. If he has a bad aux fan the high side pressure will build to the point that you can blow out the condensor coil or a refrigerant hose. The high side sensor prevent this from occurring, but it won't do this if you have the system jumped.

Another shade tree mechanic fix. Fix it right or don't fix it at all. From you previous posts I see that you are taking my advice about not fixing stuffs that breaks on your X.

[bcredliner]

I would test the fan before purchasing a new one. When you start the vehicle the aux fan is activated by the ECM for the purpose of diagnosing if the fan is working properly at 20% of max speed and then shuts it off. There is also a final stage power output on the fan housing that can also make the aux fan inoperative.

[StephenVA]

bcredliner

Can you post the steps to test the aux fan using the IMPA or other software, so the OP can get the right procedures? A few screen shots will help here also.
I do not think some of our newer readers understand that the on-board computer has built tests that will fire up devices, switches, sensors, relays, etc. All of which need a computer to send the signal not a $50 OBDII generic code puller.