Chrysler Repair: 1996 Crysler LHS Air Conditioner not wrking, pressure transducer, code interpretation

Question
hello,

I have a 96 LHS. The air conditioner will only work if i jump the relay under the hood. It's full of "freon" and I've replaced the relay (under the hood) and the "control head". The compressor only engages when I jump the relay (power to compressor?). what next?

thanks
billh

Answer
Hi Bill,
If you have the ATC control type of unit you might want to check for any fault codes it may have stored. Just idle the engine, set the temp on the readout to 75, and press and hold simultaneously the 1,2 and 4th pushbuttons on the top row until the readout starts blinking, then release them and wait for any two digit fault codes to readout. After each code appears, press the panel button for the next one. You can get a code interpretation at
www.allpar.com/fix/codes-climate.html
But from what you describe, it sounds like there is a problem that the system believes there is insufficient refrigerant. I have heard from other owners that the A/C pressure transducer in these model years was defective and was therefore redesigned. It is located in the low pressure line near the compressor, has three wires (violet/white, dark blue/yellow, and black/light blue). You can remove the transducer without discharging the refrigerant. The wires are respectively: 5V supply, signal to the PCM, sensor ground. So you might check those to verify whether you have 5v and whether the signal changes if you remove the transducer from its fitting. It may cost about $75 so treat it gently and verify that the old one isn't responding
to the change that should occur when you remove it from its fitting on the line.
Then let me know if that does the trick.
Roland