I agree with Protrash ... as far as the output to engine compartment.
If you remember my the 'rock-a-billy', I actually ran the harness out the grommet, and thru the fender well to help 'hide' the harness, but this is not neccesary.
I recommend running everything to there locations, following cleaner routes than stock, waiting till the end to tie strap. (as you might add something or change your mind)
One step at a time ... it is really easier than it looks !!