Chrysler Repair: 94 Chrysler ATC: code 36, soldering pencil, atc code

Question
the system has become eratic.
the self eval code is 36.
at times the system shuts down and the fan blows hot air.
At other times the ATC does not work but the fan doesn't blow hot.
I bought a used unit from a 96 but it doesn't activate at all. How do I repair the origional or activate the replacement?
The suplier said some times one must 'shock' the replacement?
Ken

Answer
Hi Ken,
That code says there is a failure in the communication over the digital data link connection to and from the unit. Those wires are those on pins 3 and 4 of the black plug (white/black, violet/brown).
I would check to be sure that the pins of the plug socket where they attach to the circuit board of the unit are patent. Use a soldering pencil to reheat the solder joints. If that doesn't fix it, then go to the data link connector, a six pin plug under the dash to the right of the steering column, where you will find those same two wires. Use an ohmmeter to verify there is a connection between the data link wires and the plug at the ATC head unit. That will assure that the ATC is connected to the rest of the data system. If it is, then it has to be internal to the ATC head unit.
I have not heard of "activating" a unit like this. I think you got a non-working replacement or one that isn't compatible with your '94. Or it could have a similar cold solder joint on a different pin of the circuit board (such as pin 5 of the black plug or pin 1 of the green plug which provide the current).
Roland
PS Use the 'thank/rate' tab below to get back to me without having to wait for me to be 'available' to take a question. There is a space for comments.