4X4 light flashing

[verno316]

I have done a search on here about the flashing 4X4 high light and I have read a lot of good info here but I'm not sure which of the most often repeated solutions to try first. 2002 Eddie Bauer, last night on the way home from work the 4X4 high light was flashing 8 times. Truck drove just fine, but the light would keep flashing every few minutes. Driving around town today no problems but the ABS light was on. The ABS light seems to come on during cold weather, it will stay off if the truck is restarted after being warmed up. Then driving into work it drove fine on the highway for about 40 minutes. When I got off the highway and went through a drive through I could feel "chattering" during slow speed sharp turns like it was in 4X4 and when I stopped there was a clunk in the back end and the 4X4 light started flashing. When I drove away, it drove fine but the light kept flashing. I haven't had the ABS light on at the same time the 4X4 light was flashing but it is on frequently. The check engine light is not on. I have a code reader but it doesn't do transmission codes. Would the there still be a stored fault code for the transmission that doesn't cause the check engine light to turn on? Are there any other tests that I can do to determine if it's a sensor that needs to be replaced or if it's the 4X4 module in the glove box? I have limited mechanical abilities, the module I could do myself, the sensor I may need to have someone looking over my shoulder.

 

[verno316]

Today no lights are on or flashing but it is still in 4wd

 

[verno316]

Today no lights are on or flashing but it is still in 4wd

 

[verno316]

Last night I found a harness loose. Back corner on the passenger side. I thought it had to do with the trailer hitch, but after I hooked it back up the ABS light is on solid and the 4X4 light still flashing. Tomorrow I'm gonna get my cousin to scan it.

 

[verno316]

I had it scanned today. There were several codes. The one that came up in just about every area was B1485 Brake on/off switch short circuit to battery. Though the scanner was reading correctly when the pedal was pressed. I think my problem codes are: P1867 Transmission Transfer case contact plate general circuit failure, P1836 Transmission Transfer case front shaft speed sensor failure. During the test drive the front speed sensor never registered anything.
At the start we cleared several codes that didn't come back, one of them was :C1237 Wheel Speed Rear input signal missing. Which I think may be related too?
We drove it around and switched from 4X4 low to 4X4 high and 4X4 auto. I could hear the module in the glove box clicking. I removed fuses 17 and 18 and while the 4x4 low light on the button is lit, the one in the instrument cluster is not and it drives fine.
Does changing the brake switch and the transfer case sensor and checking the ground on the motor sound like it would be the right course of action?