I hate to burst your buble, but the "dimmer" switch is just that... It dims the dash lights down in intensity, but not off... It actually makes them go from already dim to virtually not lit - but you can see it on a very dark night or locked in a pitch black garage....
I cannot remember now, but my dimmer switch is not in the dash but tucked up underneath it switched into the so called "bright" position and the switch location taken up by something worthwhile switching (like 300W worth of aircraft landign lights etc...)
I cannot remeber if you take the switch out wheter the dash lights are dim or dimmer, but the resistor is not needed in the real world anymore (if it ever was...)[:0]