QuestionQUESTION: hello, i have a 2000 chrysler 300M 3.5. my display on my air conditioner shows that the air is on.. but the air only comes through the defrost vent and the floor vent, please help, it is hot here.
thanks!
ANSWER: I'll be back after dinner, in about an hour.
thanks,
Roland
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QUESTION: ok, i will be standing by, thank you!
ANSWER: Hi Roxyie,
The system has the ability to make self-corrections and also to tell you if there is something wrong that needs to be corrected. So let us first try to take advantage of that, which may fix the problem or at least tell us what to do to fix it.
To use these capabilities, start the engine and set the temp control to 75 degrees. The car should not be in motion. Then simultaneously press and hold three buttons: the floor (lower of the 2nd from the right), mix (upper of the 1st from the right) and defrost (upper of the right-most button) mode buttons. The readout will start blinking. Then release the 3 buttons simultaneously. The readout will continue to blink. It will seek out fault code numbers stored in the body controller memory, and also try to calibrate the internal door/actuators which might cure the problem. Then watch for a two-digit number which may show on the display after a while. Note it, then press the panel button (upper of the 2nd from the right) to see any other possible numbers and keep pressing that button until the display returns to show the temperature. Write back and tell me the two-digit numbers you observed on the display and I can tell you what to do. Before you write, try driving around and use the system and see if it has regained control of the air distribution. Let me know the results of that test too.
Roland
PS Please 'rate' my answer, and where you see the question about 'volunteer of the month' please consider giving a 'yes' answer if this response merits it. Thank you.
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QUESTION: the code is #24, and the air still comes from the defroster
AnswerHi Roxyie,
That code is consistent with your observation: the door that is responsible for moving the air to different outlets, called the mode door, has failed as regards responding to the adjustment effort (feedback failure) which is likely a need to replace the actuator due to an electical failure in the sensor which sends a signal to the body computer that reports the location of the door position.
Fortunately the actuator is on the underside of the HVAC housing so there is no major disassembly of the HVAC housing itself or the dash. It requires removing 3 ducts from the unit and the floor console (the structure on the floor in the middle of the dash panel) to gain access to it. Then you remove a couple of screws and the actuator drops out the bottom. Notice the position of the operating shaft of the actuator when it drops, and position the shaft of the new actuator identically when you install it.
You can price the 'mode door actuator' at a dealer parts dept. and inquire at the shop what is the cost for labor to replace it. If that is too much for your budget I should be able to help you do it yourself with info from my shop manual that shows the ductwork.
Roland
PS: Thanks for the rating and nomination.
I looked a little further into the repair manual for the HVAC system and while I still suspect that the actuator itself has failed as regards its "feedback strip", I found that there is a long list of other possible wiring/electrical causes for the problem. However, the procedure for ascertaining which of 20 other possibilities it is extends over about 20 possible tests! That is likely to be so costly in labor as to make it a much less costly approach to just replace the actuator as I suggested and keep your fingers crossed. I conclude this because the other possibilities involve some wires to be damaged/broken (I assume no one has been fiddling with the wires under the dash) or some voltages to be wrong (which would be manifest in other issues/codes with the system that we don't 'see') so the likelihood of them is too low to invest in all that diagnostic labor time. Please let me know how this works out for you.
