Your right (of course you should be!). I pulled the sled out of the car which allowed me to work on it in the house and gave me the oppertunity to put a pot/switch on the stalk interface and play. The PIC does return values in the range of 0x00-0xff for valuse of 0-5v on the input to the A/D convertor.

Since the Jeep steering wheel switchs have low values compaired to the sony interface (mostly below 1k) , I replaced the 22K resistor in the tuner module with a 2.4K one. This should provide levels in the range of 0.1-2.8V. I have yet to test this but it shoulod work.