The OEM wiring diagrams are so much better.
Ohm out the hubs across the brn/wht and gray wires. check to ground also. I have heard of broken wires going down to the hubs. the hubs are in series.
unplug one of the hub wiring brn/wt and gray check for battery voltage from the wiring harness. Machine in forward, 4x4 switch on key switch on. work your way back from there. you should have battery voltage on both wires they are coils so the voltage goes through them.
I think You should also get power to the hubs when you press the reverse override button. My '01 scrambler does. gets power from both places but it is a different machine.
it is simple to ohm out the transmission switches and the 4x4 switch to make sure they are good. just unplug and ohm them while changing gears. brown wire is common blue/red wire high purple wire low. check for short to ground.
WOW that speedometer is important. About every wire goes into it. It looks like the speedometer takes the place of the reverse limiter on the older models.
the red/wht wire on the speedo and the cdi and the Accessory plug should all have power then to the AWD switch. out of the AWD switch gray wire to the hubs out of the hubs brn/wht to the speedometer. you may have power when the wires are disconnected but when connected nothing. so I just unplug a little way and check voltage if you have voltage there when disconnected and no voltage connected something is causing it.
Manual says clean all connections and put a little dielectric grease on connections. I squirt a little carb cleaner in there to clean.
good luck I got my own electrical problems with these things.