BMW Repair: Air Conditioning, automatic car washes, air cond

Question
About 6 months ago, my air conditioning in my 2003 325i would not put out cold air after I would go through the automatic car washes at gas stations. It would eventually start working again after maybe ten minutes. However the gauge that records the outside temperature and displays it on my dash went out. It now goes from various temperatures -40 to 120 etc. and beeps pretty much every few seconds. This however seems to directly effect my air conditioning as when the outside temperature monitoring thermastat starts doing this, my air conditioner doesn't pump out cold air. They seem to go hand in hand. As when by some act of God the temperature gauge stays constant on a temperature for a while, the air cond. seems to work fine. We already pumped it full of freon or whatever you put to make the AC get colder, but it hasn't helped. Any idea what could be wrong and how to fix it?

Answer
Ryan, I give you props for your powers of observation. Indeed if the outside temp is too low the A/C control module will disallow Cold a/c operation. (turn the compressor off) If the sensor is open it will read -40. If it is shorted together you get +122. Please replace the outside temp sensor and repair the wiring and plastic bumper corner supports if damaged. The sensor is mounted in one of the corner bumper supports. It is about $40.00 . It is about 2.5 inches long black plastic probe that points to the ground. It is low to the ground and always gets crushed over curbs and such. Please properly solder the wires and use heatshrink tubing to protect the wires if damaged. Your local BMW parts counter will help you out. If you want to pay for labor I usually charge 2.0 - 2.5 hours to repair both supports and both temp sensors and rewiring. (the other temp sensor is a round disk that is for the heated washer jets). Prices usually go down from there. Please fill out a follow up survey if this helps.
P.S. if the front parts counter guy doesn't get what you are after tell him to ask a back parts counter guy that helps the Techs all day. He'll know what you need. Don't forget the 8mm screws connectors and clips too.(If needed)
-Evan