Ok, for the A/C, we can find out exactly what codes you are getting. There is a procedure to pull AC codes from the PBU, via N22 read-out. This should help you figure out exactly what is wrong. Have a pen and paper handy.
1. Turn key to ignition position 2 (start mode, but do not start the car.)
2. Set the climate control to LO.
3. Simultaneously, press and hold the REST button and (front) DEFROST for atleast 2 seconds, or until dIA appears.
4. Press AUTO to go through each step/code. When numbers appear, record it, and pretty AUTO to get to the next one.
Once you have recorded all of the numbers, post them back on here and I will tell you what they mean. And feel free to delete them when you are finished, this way you can check back and see what codes are actually the problem. (IE... a code could have appeared once 3 years ago, and never came back. It will help us narrow down the problem.
2006 E350 w/ 155k miles (Daily Driver)
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1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)