AC compressor clutch not rotating
 

Quick brief:
The AC on my E53 is no longer cold. Toward the end of last summer it seemed to be slow to catch on (10 minutes plus high speed), but as of this summer it's simply not blowing cold at all, no matter how long the vehicle is running. Figured it was just low on r-134 but when I read the low side pressure it was at a whopping 80psi.

After finding that surprise, I figured a more thorough eval was in check. Well it didn't take long for me to notice the compressor clutch was not engaging - nor the aux fan.

I'll be checking for 12v to the compressor this evening, but still - since the AC slowly faded into submission I'm wondering what simple checks I'm missing. Would the low pressure switch being thrown lead to such high psi readings? I also discovered the AUC sensor (64116917001) was broken on the AUX fan (new one on order) - but still, the AC not blowing cold air is a different beast altogether.

Thoughts? Links?

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2005 BMW x5 (E53) 3.0i

If your AC clutch is not locking, then it is probably the coil.
you can try for a second hand one at £300, a new one at £600, but I suggest contacting Adam at [email protected] for a new coil which is a few pennies.
A straight forward job. :thumbup:

Thanks TonyinEngland - fortunately it's not the compressor. Full update to follow...

UPDATE:

Last week I checked the voltage to the compressor and it was in the 12v range. I was at a loss after that, so I took it to a neighborhood shop and asked them to test the compressor and look for anything else they could think of.

Here's the full report: Fortunately, the compressor + clutch are indeed fine and operate as expected. Unfortunately, even by forcing the compressor to engage there is still no cold air. They double checked all the fuses, checked the lines for leaks and found nothing wrong there. The AUX fan, however, still did not engage when the compressor was forced.

The head tech feels the issue might be the actual control head - has anyone experienced an issue with theirs, despite the actual climate controls working?

Also, any advice on testing the AUX fan to see if it's dead?

I truly appreciate any and all feedback on this one - yesterday it hit 99 and it's never a dry heat in KC.

UPDATE:

Last week I checked the voltage to the compressor and it was in the 12v range. I was at a loss after that, so I took it to a neighborhood shop and asked them to test the compressor and look for anything else they could think of.

Here's the full report: Fortunately, the compressor + clutch are indeed fine and operate as expected. Unfortunately, even by forcing the compressor to engage there is still no cold air. They double checked all the fuses, checked the lines for leaks and found nothing wrong there. The AUX fan, however, still did not engage when the compressor was forced.

The head tech feels the issue might be the actual control head - has anyone experienced an issue with theirs, despite the actual climate controls working?

Also, any advice on testing the AUX fan to see if it's dead?

I truly appreciate any and all feedback on this one - yesterday it hit 99 and it's never a dry heat in KC.

Did you find out the culprit?
 

I'm in KC as well, and the wifes X5 just started acting up the other day. The compressor clutch isn't engaging, and reading the low side shows high pressure, but since it's not pumping, whatever it reads would be invalid.
Just wondering....

Only way to determine if .the fan is the problem is to get it scan. A bad fan will give a DTC code, but will not set off the SES or CEL since it is not related to the engine. I use BMW Scanner 1.4 and when my fan went bad I got a DTC code for the fan. Try having the software turn on the fan but no go. Changed the fan and every thing was cleared and the AC was blowing ice cold again.

aux fan
 

Since I've been suspecting the aux fan I researched a few posts RE related issues. A few people recommended unplugging the AUX fan, starting the truck and then starting the AC - in order to check two things: 1.) Does the compressor clutch engage, and 2.) does the AUX fan show signs of life when it's plugged back in (obviously with the truck + AC still on).

So I did just that and voila - with the aux fan unplugged the compressor clutch fired right up. I checked the truck so see if the air was actually being cooled and it was. I decided to check the psi of the low side line since the clutch was engaged and I received a more appropriate reading of 50 psi (given the conditions). After that, I plugged the aux fan back in and it attempted to rotate a few times for a couple minutes and then stopped trying. It was about that same time the air inside the cabin was no longer being cooled.

Of course, I wanted to rule out anything electrical so I tested the aux fan connection for voltage and was happy to note a ballpark range of 12v.

Long story short - I'm about to order an AUX fan replacement (64546921381) but not before acting on upallnight's recommendation of getting a scan. I'll check back in with results.

Thanks for the response, upallnight - I'm having the truck scanned this weekend. Having browsed a number of air con posts - and virtually all with your positive influence/recommendations/etc - I was hoping you might chime in.

Will report back come Monday.

I don't want to blame you, but, you didn't once thought of servicing your ac even it was taking 10 min to blow cold air last summer. This summer it has completely stopped working due to lack of maintenance. One should service their ac every year as it guarantied the smooth working of system. Check over here, for more importance of maintenance of air conditioning.