Originally Posted by bubbles
I believe that fuse (no. 18) controls back up lamps, tow/haul switch and transmission control indicator light. I have read that the routing through the column of the tow/haul wires has been an issue with pinching and subsequent opening of one of the wires in the past. I think your chassis owners manual will show the location of the tow/haul indicator within the instrument cluster display.
Did you read Bubbles message Fuse #18 in the engine compartment fuse box. 20 AMP
See if you have backup lights and that will tell if its blown or not.