CAT D5C Hystat Joystick wiring

The joystick controller on my 1998 Cat D5C Hystat has 2 membrane buttons that toggle between slow/high range speed from what I understand. I have no wiring diagram- Can someone tell me what each of the 5 or so wires coming from the joystick go to? I assume the wires supply current to some kind of solenoid or contact that changes the speed range? There seems to be no speed change when toggling the buttons- so I need to troubleshoot the wiring or

whatever device controls the speed change- Any advice /info would be appreciated. Thanks

CAT D5C Hystat Joystick wiring