Headlight sensor problem: This is described in the FAQ section of this BBS. He has it wired correctly, there's just two separate dimmer settings: One with lights on, one with lights off. Set 'em both and you'll be happy.

Ground loop when adding the factory head unit: Every time you add another component to a car audio system, you create the possibility of a ground loop. This counts whether you're adding an amp, a passive crossover, an equalizer, another head unit, whatever. Each component increases the possibility that one of the components will have a different ground potential than the others. Debugging this one is just like debugging any other ground loop. Check the FAQ section under "common installation issues" for links to some good ground-loop-debugging documents.

Quiet head unit: Don't worry about it, you won't be listening to the CD much anyway. But probably what's going on is that the head unit is 0.5v or 1v, and the Empeg is 4v. If that's the case, then yeah, the Empeg's gonna be louder. The only work-around is to adjust the volumes or boost the head unit. Before you panic, check it out and make sure that he's really playing the CD player at 0db when he says it's too quiet.

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Tony Fabris