Air conditioning cool/warm lever migrates to middle

Thanks for the suggestions, booster. I went out and started the RV, turned on the air conditioning, and waited to see if the lever would migrate back to the middle. It didn't. It only happens when I'm driving around. So at least I can cool the RV when I'm parked. It appears that it isn't just the air pressure against the door. It's a combination of the air pressure and the jostling of the van. I think I'll try a small hose clamp on the cable. Maybe that will tighten it up just enough.