Q: I came off of a gravel road and discovered that the front right signal is flashing at least twice as fast as normal, while the right rear section has no lights of any kind. The electronic signal flasher is new and the rear bulbs look OK?
A: The fact that NONE of your bulbs illuminate tells me that the plug on the light assembly has become unplugged, or you have lost your ground. I read your post as none of the lights illuminate; no brake/signal, running light or backup light. So, since you've already inspected the bulbs, I'm guessing that you saw that it was actually plugged in. Get underneath the truck and inspect the grounding location for the light assembly. If I remember correctly the ground wire is connected to the outside of the passenger frame-rail (for the passenger light) about 6" from the rear-most point of the frame. Uses a small ring terminal and a bolt. The driver's side light assembly has its own ground. If it is just your brake/turnsignal bulb that is not illuminating, swap the bulb with the one above it (the are the same) and that will help you in determining that the bulb is bad (assuming that both filaments are good on the other bulb) It isn't a fuse, because the lights are not seperately fused.