Hmmmmm.... I wish I could help....I did use the stock switch but i ran aftermarket gauges. All my + wires from the lighting were crimped to one female connection to that tab on the switch.

So all the lights work? Headlights,Turn signals,brake lights, Turn signal indicators, oil,water temp,volt,fuel gauge etc etc.....except the lighting of the speedometer? Did you install any aftermarket wiring? Stock wiring?

How are the bulbs sockets? Grounded? Corrosion? Dielectric grease helps....

Once i get a chance ill put up a diagram....