Never Seen this Before, need some help.
 

hey guys, i got a 04' silverado 1500. the problem i ran into this weekend is that my brake lights go on when my lights are on. but i also notice when my lights are off and i hit my brake my front marker lights come on. i checked my fuses and didn't find anything. i was thinking that it was my brake switch on the pedal but why would my marker lights come on then? any ever seen this happen before. thanks for any advice for where to start.

Sounds like power is feeding back thru the trailer connector. Look for a green corroded trailer plug at the bumper. Also you can pull the fuse for trailer lights. Under hood fuse panel. Should be one for left trailer and right trailer. I think they are in the upper left area of the underhood fuse panel.

could also be a bad turn signal/hazard switch

Did you recently have a trailer plug installed? I would start with the wiring and plugs. It sounds like to me it's a wiring issue. Good luck!

well im going to go try pulling the fuses first. i have a light bar under the tailgate, but i bought a T harness to hook that up so its all plugins, not wire tied and its been like that for a year. its a blizzard here right now, i can hardly get out my back door. i'll try a few more things and let you guys know. thanks for all the help

well i fixed it for now.i pulled my trailer fuses and they work just fine, so im sure a wire is rubbed through back by the bumper but i can't get to it cuz its a blizzard still and my truck fits in the garage by about an inch. thanks for the help.