# Slight "moan" in climate control system



## John P Smith (Oct 19, 2004)

even when the key is not in the ignition. Sounds like a tape playing constantly. The stealer said it could be the small door behind the vent (in the climate module) that is stuck. Any ideas?


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## jaguar_wsc (Oct 10, 2004)

ya mine has the same thing going on... i thought it was the steering wheel adjusting for some reason but after further inspection, it was coming from the climate control area... sorry i cant help, but your not alone.


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## McCandless (Oct 3, 2003)

There is a small fan inside the climate control module itself that sucks cabin air in and blows it across a temperature sensor. There have been several posts on various forums on this. If the sound is coming from this fan, it should stop 16 minutes after the car is shut off.

Another possibility is the Final Stage Resistor is on it's way out and the main HVAC fan is running at very slow speed.

Any problems with the battery running down?


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## jaguar_wsc (Oct 10, 2004)

not with mine...


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## 1Dreamer (Oct 23, 2004)

I haven't had the problem, but read about it and saved the info in case I ever needed it. As McCandless (and your dealer) said, it is caused by a small fan located behind the left vent inside the climate control unit unit which pulls in cabin air and passes over the sensor measuring the cabin temperature. The fan accumulates dust over time causing the vibrating noise, but supposidly can be fixed by removing and fan, lubricating it and cleaning the dust out, but the stereo needs to be removed before you can remove the climate control unit to get to the fan. I'm not very handy so I probably wouldn't tackle it myself, but the guy writing about it said it only took him about an hour and I'd probably take the instructions he gave (see below) to my mechanics and see if they'd do it before I bought a new climate control unit - the only other option (and probably what I'd end up having to do anyway after destroying it trying to fix it myself).

*Instructions*

_"1. Remove stereo head unit by pulling off the volume nob and accessing a small "release" screw. The head unit then just pulls right out.

2. Once the head unit is removed, and disconnected there is now a large hole in the dash above the CC unit (where the stereo was). Reach in with your hands and push the CC unit out towards you. It will take some effort but the unit is only held in by a metal "spring prong" on either side. I suggest working out one side, then the other. Again be careful but forceful.

3. With the CC unit out, disconnect the 4 plugs. One plug just pulls out, one is clipped in place (and also the most difficult to remove, I had to gently pry it out), and two are locked in place with BMW's familiar "lever locking" plug, and are easily removed. If you are not familiar with the "lever lock", don't worry, it will be obvious how to remove the plugs.

4. Now you have the CC unit in your hands, and a bunch of wires hanging out of the dash, good. Take the CC unit to a safe "computer friendly" area to disassemble it. You will probably notice that dust and dirt covers the back part of the unit, especially where the exhaust outlet is. Looking in through this outlet you will see the fan, likely caked with dust. This is the culprit of that noise.

5. The goal is now to access the fan and clean it/lubricate it. That means taking apart the CC unit. It's really no big deal. You will notice the case consists of two parts, the front panel and the rear housing. These are joined merely by "snapping" them together. You will notice how they are "snapped" together, simply pry them apart. Two words of caution:

a. Do not attempt to "disengage" the metal clips, only the plastic ones. It can be done with your hands, no tools are needed. You will see why you do not want to disengage the metal clips once the unit is apart.

b. Again do this process gently, I suggest unseating all of the clips on top, then on bottom, then sliding the faceplate off, gently. Slide it straight off (not twisting or at an angle), as there is a series of about 10 "pins" that connect the faceplate to the rest of the CPU. DO NOT BREAK THESE.

6. You now have two seperate pieces. In the rear housing there is a circuit board, it just slides in and out, remove it. The fan (which just rests on its base, and slides right off) should be cleaned as well as the housing, and lubricated. Once this has been accomplished, reassemble the unit, making sure to line up the PINS carefully. You are done....almost.

7. Before reinstalling everything, hook up the CC unit and listen for that vibrating noise. If you hear it still, hold the CC unit at different angles and upside down. You may notice the noise vanishes, but reoccurs when the unit is held in it's "right side up" position. I don't know what to do about this. I assume the fan is just "bad". I disassembled the unit again, and ultimately removed the fan...and the noise. Everthing seems to work fine, and until I notice some negative side effects, I will keep the fan out.

8. Final note, when reinstalling everything make sure the wires all have enough play in them to allow them to stay connected. I noticed the plug that had no "clip", came unplugged because it was twisted in other wires, and was pulled out because it did not have enough play."_


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