Chrysler Repair: 92 transmission in limp mode, cant get fault code

Question
I have 1992 Chrysler new yorker fifth avenue 3.3 engine.   

The radio quit came back next day. Then slowed to make turn and it downshifted into 2nd and is stuck in limp mode. I have done the following: replaced solenoids outside trans including 2nd to 3rd shift solenoid, checked sensors, tried resetting by removing tcm and battery.  I have also taken it to auto zone to have a diagnostic computer hooked up, and the car will not communicate with it.

Answer
Hi Bill,
I would go to a shop that has either a Snap-on or a Chrysler dealer DRB tool and get a code readout of the transmission control module using the blue data link connector plug under the dash at the left end. Through '95 the reader is for OBD-I codes and that is why most likely Autozone couldn't read it out. Get the two digit codes, ask what they mean, then let me know and we'll compare notes with what the '92 manual I have says could be the cause.
If you believe the Autozone device was appropriate and hooked into the correct socket (not the one in the engine compartment but the one under the dash) and used correctly, then I can tell you how to verify that the socket is properly powered so that a reader will give you the fault code that you need to know.
Please read the PS below and respond to it.
Thanks,
Roland