I have no brake lights, back ups, running lights, or turn signals. Does the multifuntion switch control any of these. The third brake light does work and all the front lights work. Oh! it is a 2005 quad 2500. Any ideas?
Have you checked the fuses? The ones under the hood??
Almost sounds like a connector issue, or a grounding issue...
Not likely that the Multifunction switch is your culprit,it is your TIPM. the switches don't turn the lights on directly. They tell the TIPM that you want them on and the TIPM turns them on.