I have a 2005 sportsman 800efi that no longer has awd in reverse but it works perfectly in both low and high. I completely the diagnostic checks on the guage cluster that show the ohms of resistance going to the gear position sensor check out perfectly in each gear. I unplugged the connection leading to the front diff and the resistance in that falls perfectly within the acceptable limits and the plug coming from the cluster shows 12.3 volts when in low or high awd but when in reverse with the override button depress and all indicators on the gauge indicating that all systems are go I do not have any voltage to the front diff even with the rears spinning at any speed. I cleaned and put liberal amount of dielectric grease on connections for the gear indicator switch, the resistor for the gear indicator switch up by the battery, the connections going into the gauge cluster the lead going to the front diff and all connections going to the handlebar mounted controls. I checked for continuity of power and ground wires from the handlebar mounted controls and the ignition switch and also that power was flowing to each. Checked the four fuses in the front access below the headlight pod and stared at the wiring diagram for hours trying to see if I am missing something. I have not changed the front diff fluid as the machine works properly in forward and only has issues in reverse and I am not getting the voltage required for the system to function. Thanks in advance for any help with what direction to proceed next in completing this repair.