Climate Control - not working

All,
I have a 1996 C220.  Recently, mid-summer the A/C stop blowing cold.  Naturally I assumed it was the compressor and just drove with the windows down and started searching for a "good deal" on the compressor.  But something just dawned on me the other day (when I needed heat).  I don't believe the controller is working correctly (or how it used to).  Now when I start the car, the controller is in the "off mode" (even though I tunred the car off with it on).  When I start the car and hit the "auto button" it automatically goes to 53 degrees (not where I left it).  Has anyone experience this.  If it is the controller, how do you get the controller out of the housing?  Is there a special tool?  Is there a way to test, prior to buying a new one? Thanks.

MWK220,
At the end of your post, you asked, 'is there a way to test prior to buying a new one? 
I believe the short answer is 'yes', and the link enclosed will take you to an article by Steve Brotherton of Continental Imports in FL that explains how to get to the onboard diagnostics in the Climate Control Panel to better diagnose which component(s) may need repair or replacement. 
 
http://www.continentalimports.com/ser_ic40142.html
 
While these commands should work for your model car, a good independent tech that has access to AllData can also do the same for you.  The controllers themselves can be purchased rebuilt, or for less, you can send yours off to a rebuilder to have it rebuilt and returned.  But were getting ahead of ourselves....you asked the right question about diagnostics...run them to see as accurately as possible what's really going on with your system.  You'll save money and frustration getting this upfront step accomplished and only replacing what is really needed.
 
Bob

hmm. That sounds like a sticky situation. I don't know try this site it may help you. http://www.myhotmercedes.com/mercedes_benz_products/C_Class/Accessories

Thanks for the input.  How do you remove the climate controller?  I see two slots at the bottom of the unit, but not sure what to do.  Thanks.