Climate control issues on 2001 Chrysler Town & Country

I have a 2001 G Caravan & T&C and when the heater is on in the Dodge the passenger front blows cold air. When the AC is on in the T&C it doesnt blow on the driver side. What could cause that? What do I start replacing to start the process of elimination.

1 answer
Check here: You will see a possible answer for this problem