Originally Posted by Notoriously_rob
I keep reading about a fault in the switch. Its fairly new itself- but from autozone...will check the third brake light wires- but why the eff do the side marker lights go on when i hit the brakes
If you're talking about your front side marker lights, they are double filiment with one being the turn signal, both ts and side marker are grounded through the bulb in the front fender.
Make sure all your grounds are good. Remove the bolts in the tail lights and make sure they are clean and tight, and check the grounds right behind both headlights (under the hood)