Chrysler Repair: 94 Concorde A/C, automatic temperature control, digit code number

Question
I have a 94 Chrysler Concorde with the automatic temperature control. When I turn the A/C on the engine lets me know the compressor is going and cool air comes out... for about 30 seconds. Then the engine load goes away and hot air. It will then not work till it's sat awhile. I had the freon recharged and the mechanic mentioned the front fans weren't turning on. Is the main problem or a side problem. I did the diagnostic for the a/c and it returned no codes.

Suggestions?

Thanks!

Answer
Hi Brian,
I have thought some more about your AC problem. There is an on board ability to detect faults in the engine control system. There is a memory in the controller that gives a two digit code number for faults and that can be read out.
Try using the ignition key: turn it "on-off-on-off-on" and leave it "on" (doing this quickly, no longer than 5 seconds). By "on" I mean just the normal position when the engine is running, not the cranking position. The 'check engine'light will remain on when you leave the key in the "on" position with the engine still not running. But then watch the 'check engine' light to begin flashing, then pause, flashing, pause, etc. Count the number of flashes before each pause and keep track of the numbers. Repeat the readout and verify the counts are correct. Then group them in pairs in the order that they came out, thus forming two digit numbers. You may notice that the pause is shorter between the digits of a given number, and longer between the numbers themselves. Then send me a 'follow-up' question telling me the results of your readout. By the way, 55 will be the last number (two groups of 5 flashes each) and that is the code for "end of readout".
I have the troubleshooting manual for several engines and we can look up the possibilities of what is wrong based upon what fault codes you show. When you write back tell me what engine you are driving.
There is also an essay on fault codes at the site:
http://www.allpar.com/fix/codes.html
The code is 33 for the AC clutch circuit being at fault, and 35 for the fan relay circuit being at fault. I suspect that the controller will also kill the AC if the fan circuit shows a problem. So disregard my first opinion.
You can test the fan circuit by removing the electrical plug on the coolant temp sensor which is located next to the thermostat housing on the top of the engine (single tan/black wire). The fans should come on when the plug is removed.
Let me know what you find.
Roland




Hi Brian,
I unfortunately do not have the Chrysler shop manual and wiring diagrams for your car, just the Haynes which is not complete in this area. I would suspect that the non-function of the fans is an effect, not a cause, of the non-maintenance of the compressor function. There are, I believe, about 3 different sensors all of which must be activated for the compressor clutch to be sustained. One is a high pressure, one a low pressure, and one an ambient temp sensor. Unfortunately I can't be certain of that nor certain of the individual tests and locations of these sensors. For these reasons I can only suggest that you either try the Chrysler dealer or a highly competent independent AC shop.
Roland