my mother-in-law has an 05 grand caravan, and I have noticed that when putting the power windows up, when the window gets to the top and stops, the headlights and dash lights dim. is this something to be worried aobut?

they maybe on the same circuit. if they are, then it's nothing to worry about. when the window reaches the top, and can't go anymore but you're still holding the button, the motor draws a rediculous amount of amps, causing the dimming

Like eldiablo said, I wouldnt worry about it. My wifes 05 does the same thing.