[dsraven]

a lot of the problems I have seen over the years with dim lights boils down to a poor ground. yep, big wires, shiny new switches and connections, solder, shrink tube etc etc, but they didn't account for the other side of the circuit-the grounding. it's the weak link usually. on these old trucks, even if rebuilt (and sometimes that makes it worse because guys don't wanna scratch up the new paint for a ground connection to bare metal) the grounds get forgotten. if the battery is grounded to the body, the frame and engine it is usually the cab that gets the body ground wire attached because thats where the battery is usually. from there the ground relies on metal to metal contact through the cab to fender or inner fender mounting hardware and then rad support to fender mounting hardware (if the headlights have a ground wire to the rad support) and then the headlight bucket to fender mounting hardware etc etc. you can easily see why the circuit may have resistance built in to the ground side. it is best to run a dedicated ground wire from each light to a nice shiny bare metal spot on the frame rail of the vehicle as the frame runs from one end to the other and is better than any wire could be. then ensure the frame rail also has a battery ground cable attached to a nice shiny bare metal spot. when done all the wiring and it tests good then go to these spots and apply some anti corrosion.