Chrysler Repair: 2001 Chrysler T&C van: no passenger side heat, diagnostic capability, postal mail

Question
my climate controlled heater is nice and warm on the drivers side and is blowing cold air on the right side..'ve checked fuses and they seen to be fine..What could be the problem and can I fix or replace a computer component?

Answer
Hi Terry,
There is air deflection door inside the HVAC unit under the dash that is called zone door. That is driven by a small motor and the control unit gets a feedback signal about its position. Because of the complexity I would hesitate to start spending money on parts. Rather there is a a built-in diagnostic capability to take advantage of. I had a nearly identical question last week and here is my response:
"I had a similar question about a week ago and after looking over my '98 shop manual concluded that the best way to help was to send the pages that describe how to use the self-diagnostic capabilities of the unit, the passenger zone-blend air door actuators and the circuit diagram that operates those. They run to 8 pages of that section of the manual and I can xerox copy them on to 4 sheets of paper and send them by postal mail to you thus at a minimal cost so you don't have to reimburse me. Then you can test the system and see what it says is wrong, and have a start at the electrical and/or mechanical methods to fix it. It is a feedback system so you really need all the details which would be impractical for me to type in as text. So if you would like just use the "rate the expert" tab and there you will find a "comments" section where you can give me a postal mailing address.
Once you have the materials, see if you have what you need and feel free to write back to request more help."
Roland