Hi, this isnt a homework question, but this is one of the best technical forums Ive seen for stuff like this so I thought I would give it a shot. Im an aerospace engineering student (3rd year) and like all engineers I like to tinker with stuff, but electrical wiring like this is not my specialty. I have a gauge in my car that runs off a 3v source. I want to be able to dim it with the interior control knob that controls all the other lights (and 2 gauges right beside this one). I emailed the manufacturer about it and they said just throw in a resistor until its where you want it. I dont really like that idea since I want to be able to adjust it with the other gauges. Let me back up and say the gauge lighting is run on a constant 3v from the sending unit. The typical car system is 12v, obviously. What I want is basically a linear control over the gauge, ie, I have the knob at 6v I want the gauge at 1.5v; 12v to 3v; 0v to 0v. I asked one of my professors and he mentioned a voltage regulator, but I have never used those before... Thanks in advance.