Here is the explanation from technical manual. From schematics i noticed that 4wd switch is connected to ecm box and gnd. I will put schematic here later if needed.
4WD Circuit Operation Function:
To enable the 4WD system.
• Key switch in RUN position.
• Transmission in gear.
• 4WD switch ON.
Theory of Operation:
The 4WD circuit allows the operator to engage the on- demand 4WD system. When activated, the front differential transfers drive train power to the front wheels.
Electrical components used in the circuit include the electronic control module (ECM), neutral switch, 4WD solenoid and 4WD switch.
A solenoid-operated clutch in the front axle housing couples a drive shaft from the transmission to the front differential. The ECM controls solenoid operation.
To engage the 4WD system, the ECM checks for valid inputs from the 4WD switch (input grounded=ON) and neutral switch (input open=IN GEAR). If conditions are met, the ECM energizes an onboard relay that completes the ground path for the 4WD solenoid.
The switched power circuit supplies the 4WD solenoid. The ground connection point for the 4WD switch is located at splice SP-1
All fixed. After reading your post I realized that I actually caused the problem.
I don't like having to shift back into neutral to start the engine. My previous Gator was an 04 and had manual 4x4 selector. I jumped the neutral safety switch, so even if I was in low range, I didn't have to maneuver the shifter back to neutral to start again (and sometimes it grinds a little when I go into gear from neutral). Anyway when I bypass the switch, now the computer must think it was still in neutral and didn't need front wheel drive. After putting it back to normal, it worked again. I will eventually get a manual so I can study the wiring diagrams and figure out something better.