the dash light indicator for the 4wd keeps flickering off and on. its acting like a wire is loose but i cant find a single one that is. is there a 4wd sensor somewhere on the t-case or front axle that could be causing this?

 

Believe the sensor is on top, on the right side of the case.

 

if you have a dana 60 with the air lines comming out of the top of your t case and 2 of them go to your axle the sensor is just to the left of where the 2 air lines plug into the fork selector just unhook the wire conector and use a wrench to loosen it up but when you take it out make sure your truck is on a slope with your front end facing down because there is 5oz of GL5 80 90w oil in there and its a B***h getting it back in there and you dont want to much eather so the steeper the better.
But first jack up your front end (one tire or both it dose'nt matter) and spin a tire if your drive shaft spins you have a problem and the collar inside that housing is locking the alxe outer half shafts with the pinion. So you may have a problem I just ran in to all this last week and had to replace the vacum actuator pump cause the shaft was bent