I recently paid someone to fix the problem with the AC on my daughters car. I purchased the whole vent system. When I got it back and had the AC charged I discovered that something is hooked up wrong. When you have the heat on the AC works and when you have the AC on the heat blows. the guy that fixed it now refuses to do anything about which I will handle. Does anyone know if this is just a wire that is hooked up wrong or something else.