Chrysler Repair: chrysler 300m heater problems, conventional knob, chrysler 300m


Question
Hello Roland,

I just realized that when I wrote you a couple years back, you answered my question!! Thank you so much, I never knew it was answered!  But of course, with chryslers, there seems to be a never ending solution to the problems!  now, i am having heater problems.  When I move the switch to the fan, nothing blows. When I put the temperature the highest it can go, cold air blows out, that is also because it is very cold right now where i live, about 50 degrees and soon to get colder.  My air conditioner still doesn't work, but i never could get a final answer from shops, now that I read the help you gave to me a couple of years ago, i will definitely check it out!  but with the cold season approaching, can you please assist with what may be the problem with my heater?  thank you so much for your time and help!

Answer
Hi tyonna,
I need to know what is the model year and also do you have the heater/ac control panel with the digital readout or the more conventional knob-only design? Also are you telling me that the fan will blow, but only when set to the highest blower speed, or that it won't blow except if you ask for the highest temperature? Is the problem a lack of heat or a blown air or both.
If you have the digital control unit, it is capable of doing a self-diagnostic test of the system:
TROUBLE CODES FROM THE ATC CONTROL
The trouble codes can be checked with the ATC control if a DRBIII® scan tool is not available. The control head can only be placed into the diagnostic mode while the engine is running and the vehicle is not moving. Set the control to a 75° F setting (so there is no confusion with the 23-51 Diagnostic Trouble Codes (DTC's)

To place the system into it's diagnostic mode, press and hold the Floor, Mix and Defrost buttons (at the same time) The ATC head display will begin to blink. Release the Floor, Mix and Defrost buttons. Once the control head enters the diagnostic mode, the display on the control head will continue to blink. This occurs until it completes its tests and climate control unit door/actuator calibrations. Then it will display any diagnostic trouble codes that are present in the BCM. If there are no diagnostic trouble codes, the system will return to its normal operation as indicated by the temperature symbol (a C or a F) Diagnostic trouble codes related to the ATC and climate control unit will appear on the display in numerical form. The diagnostic trouble codes are stored in the BCM and can range between 23 and 51. The ATC control can only show one diagnostic trouble code at a time. Under certain circumstances, more than one diagnostic trouble code could be in the memory. To scroll through any additional diagnostic trouble codes, press the Panel Mode button on the ATC control. It is important that no other knob or button is pushed until all codes are read. Pushing any button except Panel Mode or turning a knob will end the diagnostic test without showing the rest of the trouble codes. There also may be other trouble codes stored in the BCM not related to the Climate Control System. These codes can only be found using the DRBIII® scan tool. Entering Self-Diagnostic Mode




ATC AND MANUAL A/C DTC's
CODE  DESCRIPTION  
23  BLEND DOOR ACTUATOR FEEDBACK FAILURE  
24  MODE DOOR ACTUATOR FEEDBACK FAILURE  
25  AMBIENT SENSOR  
31  RECIRCULATION DOOR ACTUATOR STALL FAILURE  
32  BLEND DOOR ACTUATOR STALL FAILURE  
33  MODE DOOR ACTUATOR STALL FAILURE  
35  EVAPORATOR SENSOR FAILURE  
37  BLEND DOOR ACTUATOR OUTPUT SHORTED TO BATTERY  
38  BLEND DOOR ACTUATOR OUTPUT SHORTED TO GROUND  
39  MODE DOOR ACTUATOR OUTPUT SHORTED TO BATTERY  
40  MODE DOOR ACTUATOR OUTPUT SHORTED TO GROUND  
41  RECIRC DOOR ACTUATOR OUPUT SHORTED TO BATTERY  
42  RECIRC DOOR ACTUATOR OUTPUT SHORTED TO GROUND  
43  COMMON DOOR OUTPUT SHORTED TO BATTERY  
44  COMMON DOOR OUTPUT SHORTED TO GROUND  
51  SYSTEM VOLTAGE TOO LOW FOR DOOR CALIBRATION

Let me know the specifics and we go from there.
Roland