Chrysler Repair: climate control, AC/heat, climate control unit, chrysler concorde

Question
I have a 94 Chrysler Concorde, 3.3 engine with over 200,000 miles.
Recently the climate control has started acting up. I have the AC on and then it suddenly goes to high fan with full heat coming out the defrost and floor vents. When this happens, the control buttons show no active LED and the temp LED goes off. Pressing any button has no effect.
This will last from anywhere to a minute to hours. The time seems to keep getting longer. At one point when it was not acting up, I pressed the off button so nothing was running and it still acted up and done the high fan with full heat. When it does come back it will be on high AC on the defrost vent. I tried removing the climate control unit from the dash to see if that was the component causing the problem and with it completely disconnected, it was still blowing high fan hot air out the defrost and floor vent. What component is causing this and where is it located?


Answer
Hi Randy,

There have been several others with this sort of a problem with their ATC. The best thing to do is to seek to readout the unit for whether it has recorded any fault codes in its memory, thus taking advantage of the self-diagnostic abilities of the unit. You will have to do this when the unit has an LED display, so be ready to do it when that occurs:
On the ATC console there is a self-diagnostic capability that you can get to give you a code number as to what is wrong. Just set the unit for 75F, idle the engine, and then simultaneously press the floor, mix and defrost buttons (which are the first, second and fourth on the top row) and hold them until the display blinks, then release the buttons. The control display will then show a two-digit number if it has caught a problem. Then press the Panel button (first button on the second row) to see if any more codes come out. When the panel button push results in the display returning to 75 all the codes have been displayed. Either write back with the code numbers or go to www. allpar.com/fix/codes-climate.html for a list of code translations. I have some info on the various components and how to service them, but we need to get the code to go ahead.
Roland