Originally Posted by manitu
Any one else think this will work? I'm useless when it comes to electronic know-how. But would like the optimal lighting.
I've messed up more than one car screwing with the electrical, and would like to believe I've learned my lesson.
One thing I'm not sure of is whether your Driver Information Center (DIC) is going to get confused over the current flow to the different headlights, and maybe start giving you bogus warnings about a headlamp out. The warnings are sent out by a controller in the dash called (if I recall right) the Adaptive Lighting Unit, or something like that, a/k/a the ALU (or maybe Adaptive Lamp Monitor -- ALM? Whatever...). It monitors current flow on the lighting circuits, and sends a warning to the DIC if flow on one circuit suddenly decreases, to tell you that such-and-such a bulb is out.
I remember me and the dealer going crazy over what looked like false alarms from the ALU about the high-mount brake light in the back window, which of course always worked when you got out and looked at in the parking lot, but then when you're driving, the warning would start chiming again. Finally found a loose connection in the bulb socket, just loose enough that body flex while driving would make the bulb flicker. So the warning system had been right all along...
I think you should just temporarily wire in the relay, maybe by just sneaking bare wires into the socket plugs or however you can avoid cutting wires, and just make sure it will work without giving you false alarms whenever you switch between high and low beams. I have no solid reason to think it will go nuts, but I haven't done this setup on a car with a lamp monitor before. If it acts the way it should, then solder in the new wiring setup and relay, and you're all set.