Your truck is screwed if you have those lights, may need a new rear differential to fix the problem. Comes from the driveshaft pushing around the gears in the differential, then when the truck is moved the gears just grind the teeth away, normally can't even feel it or hear it too!
I'm kidding, your ABS plugs most likely either snapped intwo, or jst disconnected from he connector on top of the frame, happens when they are not disconnected like they are supposed to be before dropping the truck.
Find those little random wire things on both sides of the rear that are near the rotors , and follow the side that goes up towards the frames of the car and see if it is disconnected. If it is, reconnect it (connectors are hidden ontop of the frame), if it is connected, then that means your just snapped the wire in two somewhere.
I anwered this only because you installed the Pedders package that I used to have
, and because I ignored your last message to me because I was in a bad mood that day. This topic has been answered by me, and a few others before, so anyone who needs help next time should hopefully find this response, because me and most other prob. won't answer it!