I am having trouble with the heater and A/C temperature ****, you have to turn it to full left for cool air or full right for hot air, it doesn't work adjusting it to the middle for warm air. If anyone has had this problem could you walk me through the steps to replace switch or clean it if possible.

 

I believe it's one unit, you can't take it apart. You can get it through Napa and easy to replace, 4 screws and a few plugs.