Unlike incandescents. LED's have a specific positive and negative. What has happened is that some LED's have been installed backwards and the positive is back feeding through a negative wire causing the problem.
The center post of an incandescent socket is positive and the metal side on the socket is the negative. Reposition all of your LED's so that the positive post is in the center of the socket and the negative is at the sides.
If the bulb is the type that just pushes in like an number 7443, then one side of the push socket is positive and the other is negative. Just turn the bulb around and reinstall. If is is a bayonet type base like a 1157 bulb, then identify the positive of the LED and make that contact with the bottom of the socket.
NOTE: this has nothing to do with the truck. In fact if the LED's are all installed on the trailer only, all the truck recognizes is the electric load not the type of bulb. Now replacing LED's on the truck itself, that can cause issues.
