Dodge Repair: 04 Ram 3500 Diesel AC, poor connections, ac system

Question
My AC system has begun to blow considerably warmer from the right two vents vs. the left two.  I am getting a P code of 2509. Is this an actuator problem, or related to the PC board for the controls.  Is there any way to diagnose the actuator without removal, i.e. apply voltage to open/close from the control panel?  Could this be a vacuum issue? As the actuator is not easily accessable, I'm hoping for an external cause/fix.
Thanks, Terry

Answer
P2509-POWERDOWN DATA LOST ERROR


When Monitored: Continuous - key on or key off.
Set Condition: Loss of voltage detected at the ECM for a calibrated amount of time.
POSSIBLE CAUSES
POOR CONNECTIONS AT THE BATTERIES
LOW BATTERY VOLTAGE
OPEN FUSED B+ TO ECM
OPEN GROUND CIRCUIT
BATTERY + SHORTED TO OTHER CIRCUITS
RETURN CIRCUIT SHORTED
BATTERY + SHORTED TO GROUND
INTERMITTENT CONDITION