[RandyP]

They share the freon from front to back, so that should not be your issue. I've never taken a burb with rear A/C apart to be sure what is back there, but I always thought they shared the compressor and all that was in the back is a blower and evaporator core at most.

Does it do anything in the front when you slide the cold/hot lever? If there is never any temp change when moving that, even on Vent or defrost, I'd say that is your problem and start chasing those components to find the fault.

I'm really like you though, I am not an A/C guy beyond hooking up the low and high lines and doing what the A/C machine tells me to do.