I'm the original owner of an '02 FWD Warner Bros Venture with 210,000 miles. The only problems I've had were intake gaskets and oil cooler at 184,000 miles. My rear heater blows hot all the time regardless of the front control or if I have the front control on "R" the rear digital controller. The fan control is fine, just the temperature is always hot.

I've pulled off the rear convenience panel where the air compressor switch is and can see the rear HVAC unit but don't know what I'm looking for.

Thanks