Question about 1999 Chrysler 300M
This problem is caused by the miniature light bulb inside the climate control display being burnt out, remove the climate control module from the dash and then remove the top cover of the control head, inside the control you will find a tiny twist in bulb socket just behind the display face, this is what lights the display up, it is called the back-light illumination bulb, remove the bulb socket by twisting it counter clockwise and then replace the bulb..
Posted on Oct 15, 2009
The possible causes would include the body computer,wiring and the mode door actuator motor.I am sorry to say that these other components will need to have most of(body comp) or all off (actuator)the dash removed to replace them.
On most models, motor is on the bottom of the hvac housing and can be seen if you look on the drivers side above the trans hump and accelerator pedal area.it is a black box with three black screws holding it on and a connector with,i think 4 wires. before you go there lets see if there is any codes in the control head. ATC SELF DIAGNOSTICS
The ATC system can be diagnosed two ways. The scan tool (DRB) can be used or the vehicle's own control head display may be used. If the scan tool is to be used, refer to the proper LH Body Diagnostic Manual.
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 23-36 Diagnostic Trouble Codes)
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 Entering Self-Diagnostic Mode When the control head display begins to blink release the floor, mix and defrost buttons. Once the control head enters diagnostic mode, the display on the control head will continue to blink. This occurs until it completes its tests and 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 temperature display.
Diagnostic trouble codes related to the ATC system will appear on the display in numerical form. The diagnostic trouble codes are stored in the BCM and diagnostic trouble code numbers can range between 23 and 36 Diagnostic Trouble Code Chart for The control head 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 button.
If diagnostic trouble codes are found, refer to the proper LH Body Diagnostic Manual for repair procedures.
The control head cannot display all diagnostic trouble codes stored with in the BCM. There may be other diagnostic trouble codes in the BCM not related to the ATC system. These codes can only be found using the scan tool.
ERASING DIAGNOSTIC TROUBLE CODES
Diagnostic trouble codes can be cleared from the memory two ways:
* The scan tool
* Power to the BCM can be disconnected for ten minutes (disconnect battery)
If you will get codes like 23,24,31,32,33, then :-
it would tipicaly have a mode door/mode motor problem.here is some info on the circuits of that motor. MODE DOOR ACTUATOR (ATC)
The mode door actuator is located on the lower left side of the A/C- Heater housing. This actuator controls the position of the panel/bi-level door and the floor defrost door.
Power for the mode door actuator is supplied on circuit C26 from the Body Control Module (BCM) This is a 5 volt feed.
Circuit C35 is the mode drive circuit from the BCM. to the actuator.
The C37 circuit is the feedback from the actuator to the BCM. The BCM uses this information to adjust the door to the proper position.
Circuit C57 is the sensor return to the BCM. This circuit is spliced with the other actuators in the housing.
Circuit C34 is the common line that is spliced, and connects, to the other sensors in the housing.
here is info to replace. The mode door actuator is an electric motor. It mechanically positions the A/C unit panel/bi-level door and the floor/defrost door. This actuator contains a feedback strip which allows the computer control to know the exact position of the mode door at all times. The mode door actuator is not serviceable and must be replaced if found to be defective.
The mode door actuator is located on the lower left side of the heater housing Mode Door Actuator Location
1. Remove left and right under-panel silencer/ducts.
2. Remove floor console.
3. Remove center floor heat adapter duct.
4. Remove rear seat heat forward adapter duct.
5. Loosen center support bracket and pry rearward to gain access to the actuator.
6. Remove actuator retaining screws. Then pull actuator straight down. Upon removal, note the shaft position of the actuator, because the shaft on this motor is keyed. When installing new actuator, its shaft must be positioned in the same location.
7. Remove electrical connection on actuator. the connector pin out goes like this, pin 1 is c35 dark green and yellow, pin 2 isc34 dark blue and white, pin 3 is c26 pink and dark blue, pin 4 is c57 gray and tan, pin 5 is red c37. OK so basically pins 1,2,3 control the motor with the 5 volt on pin 3 and 1,2 switching ground to change motor direction. typically what i would do in the shop setting is remove the connector (maybe the motor too,i cant remember specifically) and plug a new motor to it and see if it moves(a benefit of having a parts department)then I would also try and move the door shaft by hand to make sure it moves(you can go key on and run the fan to make sure the mode has changed).just a note,I have had some where i have taken off the motor and it moves but is not strong enough to move the door. if you dont have any motor control(you can use a dvom to test for voltage and ground)it may be wiring or the body control module(since you replaced the control head).
Let me know, if need further assistance.
Hope i helped you.
Thanks for using ' Fixya ' and have a nice day!!
Posted on Oct 05, 2009
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Posted on Jan 02, 2017
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