first off let me start by saying that i have replaced all the bulbs on the drivers side trying to figure this out. i have a 2002 sunfire and when i turned on my lights they all work except the front left marker light. when i turn on the signal it did one of two things, it will either rapidly flash like a bad bulb, or it will turn them on constant and make a squealing noise. oh and my drivers brake light doesn't light up when i step on the brake. all the fuses are good too. Now the front and side marker work fine, flash right speed and everything, but the drivers brake light still doesn't work. any suggestions would be greatly appreciated!

I would go through and check all the wiring. Doesn't really sound like the multifunction switch to me.

Maybe someone more knowledgeable than me in this can chime in.

sounds like wiring to me as well. When I was wiring in the S15 headlights I would get that wierd buzzing/squeling noise when not hooked up correctly.