Today it is hot (90s), and I have been stopping and starting for a couple of hours. I stopped for about 15 min, and when I went to start again, the AC was DEAD. No lights on the dials, no blower, nothing. Everything else is working (lights, radio) I could not blame my ICELINK, be cause it is disconnected from the trunk.
So I thought I blew a fuse. Then I stopped again for less and 5 min, and voila! AC started working again like normal.
What the hell is going on? This is not an attractive quirkiness.
Am I going to see more trouble out of this?
Can anyone offer insight as to what happened, and how can I prevent it from happening again?

 

Is the problem you described recurring regularly, or was this a unique experience?

My auto temp. has exhibitted being totally dead (ie. no display on the dial) a few times over the 3 years I've had my '04 MCS. Turning the car off then back on cleared up the problem for me.

 

Many a/c compressors have a relay which cuts off the a/c if the compressor freezes, which happens most often on very humid days. However, I never heard of one that actually turns off the whole a/c circuit.

 

I remember hearing about a TSB on a grouding issue with the auto climate control system. It hasn't happned to me yet, so I can't recall the exact info. But I recall something about a weak ground causing the system not to power on at random intervals.

 

I have had this happen with my '02, and it seems to happen only when it's in the 90's and it's stop and go, like a near traffic jam. Then it worked as normal when I was able to get the car up to speed again. My theory is that this behavior is the computer detecting the engine getting too hot for a/c use, so it is protecting itself. When my a/c went off and back on, I never shut the engine down, so clearing a code was proven not necessary. I don't believe my engine temp gauge, because it has never exceeded half way up the scale- not even when it's really hot outside. The radiator fan can be wailing away, but there's no place to move the air to in that little engine room- so I believe it gets hotter than indicated. -Jeffy.

 

This happened only once. I have an 04 MC with auto climate control.
I was driving around town, with lots of stopping and switching the car off (about 3 separate stops) before this happened. Then I rode for about 4 miles w/o air, switched the car off for 2 min and when I started again, it was working.
Admittedly, there was one procedure I did not do when the air failed: Normally when I start my MINI, I turn it to position I and wait for that self-test to run until the red light on the fuel guage goes off, then I crank. This time I did not.
Now, I do not know if this self-test thing is an urban myth, but I have been doing it since reading about it here at NAM. Sometimes, I forget and nothing bad happens. This time, I forgot, and the air failed. I have no idea if it is related.

yes it was hot, but not great humidity; still the compressor could have frozen.

 

I had this happen once with my '03 MCS, but it was not a 90* day.........restarting the car "fixed" it, and it hasn't done it since........I blamed it on the terrible blowing rainstorm we had the night before, because my wipers and auto locks also did not work. A few hours in the hot sun that day and everything was fine. I'm now wondering about a bad ground as mentioned before. Any better info on where said ground connection is located?

 

This happened to me last night. It was in the mid 20s when I stopped. The only thing I can think of was I left my TomTom plugged in. When I started the car, everything was working fine except the Auto Climate unit. This morning everything was fine. Very strange.

 

I have a tip that may help ALL of you ...
I did post this on "things you didn't know "

here is a short version >>>

Every time you put your key in the ign and turn it to the ON position (not start) the computer does a check of functions (and starts that check at a different section each time ...
Heater , Ac , windows , sun roof ... you get the picture ..

If you turn the key to start, it interupts that check (maybe just the check it is currently doing)



Proof put your key in and turn it to on (not start) look at the loest indicator for the fuel level ... it will be RED ... not orange ... when the lowest indicator changes color to orange the fuel check done ...
The BMW system checks fuel LAST ..so when that light is orange you are NOW ok to crank the engine...

(this check will not work if you are low an fuel ...as the indicator will remain red anyways)

If you put the key in and turn the car over really fast it can miss or interupt the check sequence...
This will correct it self usually after 3 start checks if there are no actual issues.

So...
make it a habit to get in turn the key to on ... take a breath / pause a moment before cranking the engine.

 

Good to know! Thanks!