[RustyPile]

I too, know nothing about Dapper Headlights.. Here's a detailed explanation of how the dimmer switch works.. Its a single pole, double throw switch. The headlight bulb has 2 filaments and 3 terminals, one for hi beam, one for low beam, and the third is ground.. Each headlight has its own ground. A blue wire from the headlight switch brings voltage to the common terminal of the dimmer switch.. A tan wire carries voltage to the low beam bulb terminals. A green wire carries voltage to both the bulb's hi beam terminal and the hi beam indicator bulb in the dash. Voltage is not sent to both hi and low beams simultaneously, only one at a time.

To test the dimmer switch, disconnect the plug. Using a DVM, check continuity between the blue wire's terminal (common) and the other 2 terminals. Depressing the "button" selects continuity between the blue wire and the other 2 terminals.. Again, continuity between the blue and the others is selective, only one at a time. Any other results means the switch is bad. If the switch checks good, check your wiring again...