With everything turned off. My headlights and tail lights won't turn off. And I have a burning smell in my cab. I pulled a small black plug. That's in my fuse box. Thinking its a fuse or a relay. My maintenance manual doesn't identify it. I pulled it. And my wire harness just above the fuse box started smoking. Wanted to know if someone knows the problem before I take it in to the dealer and save the cash. The dealer will charge me just to look at it. It's a ford f150. Super crew. 4.6. 2008.