It's not whether or not the doors moving but whether the temperature control affects the temperature change.
Check out the procedures below:
Do you have a Laramie with Automatic Dual Zone controls or Manual Single Zone Controls (with the 3 knobs)?
24 - Heating and Air Conditioning / Diagnosis and Testing
Before performing the following tests, see Group 7 - Cooling for the procedures to check the engine coolant level and flow, engine coolant reserve/recovery system operation, accessory drive belt condition and tension, radiator air flow and the fan drive operation. Using a scan tool, check for any Diagnostic Trouble Codes (DTCs) in the A/C-heater control, Totally Integrated Power Module (TIPM), Powertrain Control Module (PCM) or Engine Control Module (ECM), depending on engine application. Repair as necessary (Refer to 28 - DTC-Based Diagnostics/HVAC - Diagnosis and Testing).
MAXIMUM HEATER OUTPUT: TEST AND ACTION
Engine coolant is provided to the heater system through two heater hoses. With the engine idling at normal operating temperature, set the temperature control to maximum heat position, the mode control to the floor position, and the blower motor control to the highest speed position. Using a test thermometer, check the temperature of the air being discharged from the floor outlets. Compare the test thermometer reading to the Heater Temperature Reference chart.
View attachment 916650
OBSTRUCTED COOLANT FLOW
Possible locations or causes of obstructed coolant flow are as follows:
- Inoperative water pump.
- Inoperative thermostat.
- Pinched or kinked heater hoses.
- Improper heater hose routing.
- Plugged heater hoses or supply and return ports at the cooling system connections.
- Plugged heater core.
If proper coolant flow through the cooling system is verified, and heater outlet air temperature is low, a mechanical problem may exist.
Possible locations or causes of insufficient heat due to mechanical problems are as follows:
- Obstructed cowl air intake.
- Obstructed heater system outlets.
- Blend-air door(s) or actuator(s) not functioning properly.
- Faulty blower motor system
- Inoperative A/C-heater control
If the heater outlet air temperature cannot be adjusted with the temperature control on the A/C-heater control, the following could require service:
- Inoperative A/C-heater control.
- Inoperative blend door actuator(s).
- Inoperative, obstructed or improperly installed blend-air door.
- Inoperative related wiring harness or connectors.
- Improper engine coolant temperature.