Just remove the wires from the dimmer, and clamp them together with a screw and nut. If the lights get brighter, replace the switch. There should be one hot lead coming from the light switch, and two leads leaving the dimmer, one for high beam, and anothet for low. WITH THE LIGHTS ON, check the voltage from each of the dimmer switch output leads to ground. I'll bet one, or boith of them is low-voltage. The circuit MUST be complete, and operating, before voltage-drop tests work.
Jerry
