heater/AC issues

[JOE131313]

I own a 2004 Dodge Durango. I started having trouble with the heater/AC controls about a year ago. The heat and A/c constantly stays on. It never shuts off. If I shut the power off to the controls it actually blows harder. The heat and A/c does work in the truck but is frustrating because it never shuts off. Brought it back to the dealer and they told me that a valve was stuck open. They "fixed" the problem and it worked for about 2 weeks. Then the problem would come and go. Know for the last couple of months it has stayed on and I can not shut this off. Does anybody know where this valve is located or how I can try and fix this issue.

Next issue about a month ago the digital display that controls the heat and A/C when down. I can not see the temperture or anthting on the controls besides my radio. This problem also started about 2 months ago. It would sometimes come on and sometimes not come on. Know it has been off for some time. I am assuming this is a eletrical problem which I would have to take the whole dash apart?

Thanks in advance for any help