Yeah, the dimmers are not resistive, instead they give 12v and vary the frequency so the light is basically flickering on/off really fast and the human eye perceives it as dimmer. Makes the system work with LEDs and stuff (how late model falcons etc do it).
The trick for modders is that the wiring shows 12v with a digital meter, but will show a varied voltage with an analogue meter (as the analogue meter works much like a lightbulb).
I'd say the switch thingo is fried
A.