I believe that model has a pressure tansducer on the steering drag link to send a signal to the steering servo. One side of that could be bad as it monitors in a push pull type of manner to adjust direction.


The other possibility and most likely is in the back SCR panel behind the steering board there are 2 transistors on the top right very small in size one is for turning left, the other for right! check the wiring and make sure wires haven't loosened or broken off at the terminal.


When removing the large steering box make sure truck is unplugged whereas if the box touches a contactor bar it will blow it internally and its $1500 bucks. Just let it hang to the side with a block holding it.


This is based of my CSPO1L - CYBO2L


EDIT: A simple test is to swap the transistors if your problem is reversed you know its that transistor.