2002 TRX 450 Foreman - 4x4 not working right

I have a 2002 TRX 450 Foreman S with the switch operated electric 4x4. The 4x4 is not engaging properly. I have it up on jack-stands now to diagnose the issue. What I have observed so far is:

1. At start up I can engage the 4x4 toggle switch and the front wheels will spin up through 3rd gear. They do not operate in 4th or 5th gear.
2. Once I shift into 4th or 5th gear the front wheels are no longer driven. Downshifting into 3rd, 2nd or 1st does not re-engage the front wheels.
3. Shifting into neutral and then back up into 1st does not re-engage the front wheels. Fiddling with the toggle switch while in neutral and then upshifting does not re-engage the front wheels.
4. Once shifted into 4th or higher gear the front wheel drive will not re-engage without shutting the machine off and restarting.

I have the front fender covers off an have not found a loose wire yet but I do not know where to check. Does anyone have any thoughts about this issue?

Thank you.