Check for power at the switch (brown is always hot, blue goes to the headlamps) If you connect the brn to blue the lights should work. If not, suspect the dip switch, it has 3 wires, blue is hot going in (center terminal) connect the blue to either other wire, low or highs should come on. If not, check the dip harness where it meets the headlight harness sort of near the coil, look for 3 wires blue, blu/red, blu/white.
Clean those connections and make sure the ground is clean and connected at the inner right fender sort of behind the heater hose clamp, that is the headlamp ground.