I have a painless wiring fuse block under the dash, that is the easiest/safest way to get power for accessories IMO. Dimmer wire is in the light switch or other areas of the dash (i. e. lighting for the center dash). It is a Orange wire with a white tracer, I think. I can't remember what the tracer color is, just use a test light to make sure you get the right wire.
hope that helps