Anybody know anything about defroster/ac switch on vision?

[alcoon61]

I have been fighting a/c problems for couple weeks on 07 cxn 613 vision. Everything under hood and freeze switch has been replaced and is new. I keep getting a chatter behind the controls like a relay chatter and thought it was the freeze switch. I finally isolated it last night to the switch mounted on back of the the defroster control housing bottom right corner with two wires going in. It has a little shaft that goes over to the defroster pot on the back side. I can tap on it when a/c kicks out and a/c kicks in , it is constantly in out when in the vent selection for a/c though. I can turn the knob to defrost which forces the rod to move and the switch comes in. Is the main power using the same contacts on this switch? thought about just adding a toggle and remove the switch all together then the a/c would stay on. Any insight would be a big help.

thanks

[SD40T2]

I have been having the same problem as you describe, it is also a '07 613. After I read your post I tore my dash out and checked the switch that you described and cleaned with contact cleaner, while this did not solve the problem, what I did find is that the on/off switch circuit for the a/c is the source of my problem, it is a printed circuit board with a couple of resisters and a timer(which is the "clicking" sound you hear) to cycle the compressor, I beleive one or more of the componants is bad or weak, although it is probably pricey I feel that the heater/ac control assembly should take care of this problem. I currently have the compressor on a switch so it works however you need to turn it off occasionaly to keep from freezing the system. I have been trying to find this problem for 2 years so I feel your pain, what i might try next time I have the truck home on a weekend I am going to try to remove the on/off switch and solider another switch and see if that takes care of it if I can't get the shop to get me a new control. GOOD LUCK!!