My truck has been demoted to non-TRD now

Ok in some need of answers and help. Last week my truck was kind of acting weird, whenever i would stop and go the passenger side rear tire would not want to move almost. It was almost like the brake was grabbing and keeping it from rolling. So this morning I took it to a shop to get the brakes checked out. The mechanic, a well trusted family friend, called me and said that it wasn't the brakes because when he put the truck on the lift, he could spin the wheel freely AS LONG AS THE TRUCK WASN'T RUNNING, but the moment he cranked it up the wheel would seize back up. He told me n my dad that it was the diff lock causing it. So as soon as we got home, we started looking for a fuse to pull, couldnt find one so ended up disconnecting the wires that pulg up to the differential lock. Anyone have a clue on whats up???
one other thing the diff lock light has been flickering to on for a months now, but now that we've unplugged the diff wires, it gone.

 

Ben your a stinking genius!!!! I'll check it out Friday when I get back from school.

 

Ok, I've got a lever not a switch t-case.