Passenger side will not change temp from hot to cool

Hello, This is nearly guaranteed to be a blend door, or blend door actuator. They are located in the HVAC box, which is mounted behind the dashboard. Some are accessible from under the dahsboard, but others require the entire dash to be removed. If the dash must be removed, I do not recommend trying it out at home, unless you are very experienced with automotive work. See below for certified shops in your area, or let me know if you have other questions. http://repairpal.com/dodge-within-10-miles-of-morton-illinois-61550