I am having the same problems on my 97 1500. Third brake light, backup lights, and taillights work but main brake lights, hazards and turn signals don't. All front-end light functions are working. After reading some threads and looking at the diagrams in my Haynes Manuel, I decided to try the multifunction switch, brake switch, and headlight switch from the junk yard with no improvement. I even checked both multifunction switches for continuity and my old one had a problem with #11. I have the factory tow pkg so I thought that might eliminate a hack job but I have not checked the ground. I just sign up here so I am a newbie but I have been trying to read different threads for a while and it seems there could be a few different culprits here.