99 Chevy Tahoe AC/Heater Switch Issue

I have a 99 chevy tahoe 4x4 5.7 old body style. I am banging my head trying to figure out whats wrong with my AC/Heater Control Switch. I have switched it out twice now, the first time I did it the control would only work on high and would intermittently work. Put a new switch in and worked great for a while then started doing the same thing, then when I would bang on the fan motor it would work again so I bought a new fan motor replaced and all was good for about 3 weeks now it will shut off again at any speed and might come on if you hit a bump right or just as it feels like working. So last night I tore the dash off again:headshake and found that the connector to the switch has a burned/melted spot on one of the connections, so could this be my problem? Is that burned spot causing me to short out and kicking the blower off. The fuses are all good and the correct sizes so I know thats not my issue. Husband is out of town so I am working on this myself and feel I have become pretty familiar with all the issues at hand. My other question is if I want to check the amps coming in at position 1,2,3, and 4 which wires to I check on the harness at the switch? The wire that is burned it the brown wire if that helps anyone. Any help for this girl is much appreciated. Another thing and not sure if its even related but I blew a fuse on my brake lights and turn signals the other day so not sure if that is related to this issue or not!! I am also assuming that this problem is not a resistor issue?

The brown wire is power coming into the control module from the HTR-A/C fuse. So, yes, this could be the problem if it doesn't have a good connection. As far as the resistor pack, this is also an area of concern.