2003 Tacoma 4wd w/Selector switch won't engage

New to the forum. I have a 2003 Tacoma pickup that has a 4wd selector switch to engage the system. When you depress the switch nothing happens. Took the vehicle to a Toyota dealer and was told they didn't have an idea, but they suspected the ADD actuator was bad. Started troubleshooting the system this weekend for myself. Making a long story short, this is what I have discovered.

With the 6 wire flat connector connected to the ADD actuator, nothing happens when the 4wd switch is selected ON or OFF.

If I disconnect the 6 wire flat to the ADD, then switch the 4WD Selector to the ON position, the differential actuator cycles in to 4wd. If I switch it OFF, the differential disengages. this is repeatable.

With the 6 flat wire disconnected, then switch the 4wd Selector to the ON position, the differential actuator engages, just as this completes I connect the 6 wire flat, then the ADD actuator engages and the 4wd light illuminates in the truck. (I've confirmed by driving that the truck is definitely in 4wd). When I depress the 4wd Sector switch to OFF, the ADD actuator and the differential actuator both disengage, however, the 4wd light stays illuminated until I disconnect the 6 flat wire connector to the ADD. This sequence has been repeated numerous times.

Started to wring out the wiring to the actuator and have discovered the following:
Pins 1,4,5 Unknown.
Pin 3, 10-12V all times.
Pin 6, Goes high(>9V) for approximately 1 sec when 4wd selector switch is turned ON
Pin 2, Goes high(>9V) for approximately 1 sec when 4wd selector switch is turned OFF

Wondering if anyone has experience with this system and can suggest further troubleshooting?
Anyone have a wiring schematic?

Thanks for your time.