Climate Control Problem
 

Ok im start from the beginning. I got a 1992 full size blazer with 4wd, 5.7. Got about 218k on the dash. One day last week I was driving down the road and my heat stop working. I noticed that my climate control module was not lite up. The next time I restarted the truck the a/c light would flash for about 2 mins then the heat would kick on. That went on for like a week, then it went blank again while driving. After that the heat would work itermittenly. I decided to change the cc module. Replaced it and everything worked fine for about two days and then it went blank again. Only this time when I get in the truck and start it the three buttons for fan, direction, and up/down stay dimmly lite, but go off when I hit the light button. My question would be if I am going to trouble shoot this problem assuming its a short in the wiring to the module and not the module itself where do I start ? If someone has had a similar problem please point me in the right direction. If this has already been discussed in detail please point me to that thread. Thanks in advance.