4WD light blinking, how do i check all the sensors?

Hello, and thanks in advance. I am still digging through the forums and trying to find something which will apply to my scenario, but it's 6:40 pm and I was planning on using my truck tomorrow, so I am trying to diagnose and fix ASAP.

Some background- I have a 2002 tacoma with manual transmission, button shift 4WD. A couple months ago I added the URD piggyback ECU, smaller supercharger pulley, larger injectors, and an AFR gauge. Everything was great for a while, but then I started getting this open loop fault, with a faulty heater circuit code. I can reset the code and it runs perfect (verified by the AFR guage) for a couple hours or days with no problem. I tried replacing the O2 Sensor with no change. I suspect it is a loose ground somewhere, but I haven't investigated that yet. Today I was cleaning up some wiring (from various added lights, winch, afr gauge etc.), so I had the dash apart, then I put everything back together and went to back my truck up to my boat to tow it tomorrow. It is running fine, and entering closed loop mode (at least at the moment).

The problem- My truck started blinking the 4WD light, I didn't press the 4WD button, or shifter. The actuator did not move, the transfer case is in 2WD, and both front wheels are not engaged. When I press the 4WD button it does nothing.

So far I have checked- the 4WD button, all working fine. I had to replace the transfer case several years ago because of a cracked housing, I kept the old actuator just in case I needed a new one some day. I connected the wire connectors to the old actuator, and the body to ground, it does nothing when the 4WD button is pressed, and the light still blinks constantly, so I do not think it is the actuator. I think it is a bad sensor, bad connection to a sensor, or bad ground somewhere.

My Haynes manual doesn't have very much information about all of the sensors involved, so any help would be much appreciated. Any ideas are welcome, bonus points for ideas which relate it to the open loop fault, or me having the dash apart today.

 

Also, the connector on my actuator is a different shape than the Haynes manual, and a lot of information online. It is 6 pins in a row, not 3 and 3. The wires going from left to right are blue, white, yellow with red, white with black, nothing on pin 5, and pink. If anyone could help me identify what voltages/resistances these pins should have that would be very helpful.

Thanks

 

I traced the problem down to a severed wire behind the dash, must’ve sheared it somehow when putting the dash back together. That wire was the ground to the transfer case sensors