If you are getting heat only on the pass. side then I believe the blend
door has failed. Dodge has a fix and the job is not easy as almost the
whole dash needs to come out in order to get to the heater box and the
door. I have read that a simple flush of the heater core will cure it,
But that diidn't work for me. I think because dual climate control was
an option the door is set up to control the two sides of the cab. When
it fails only the pass. side gets heat.
Unfortunatly you do have to remove the dash to access any of the blend door or fresh air door actuators
here is a step by step proceedure this takes aprox 5 hrs in a shop so plan on a weekend at home good luck
FLOOR - DEFROST DOOR ACTUATOR
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY
NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM
CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN AN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
Disconnect and isolate the battery negative cable.
Remove the instrument panel assembly from the vehicle.Fig. HVAC housing, dual zone shown (single zone similar)-nut (1),
passenger blend door actuator (2), nut (3), inlet baffle (4), recirc
door actuator (5), recirc air door (6), driver side blend door actuator
(7), HVAC housing (8), bolt (9), defroster door actuator (10), mode door
Remove the electrical connector from the actuator.
Remove the mounting screws from the actuator.
Remove the actuator from the HVAC housing.
Install the floor-defrost door actuator to the HVAC assembly.
Install the mounting screws and tighten to 2.2 Nm (20 in. lbs.) .
Install the actuator electrical connector.
Install the instrument panel assembly into the vehicle.
Connect the battery negative cable.
I suggest check (or replace if is necessary), the blend door it is a huge project you have to remove the
dash board. There is a repair kit available either way it is a 8 hr shop