I noticed when turning on my turn signals that the corresponding dash indicator would stay lit and not flash only when I was hitting the brakes. When I got out of the truck to check my turn signals I noticed that both rear signals were flashing along with my canopy third brake light and the factory third brake light but only the correct front signal was flashing. I decided to just replace both front, both rear and the factory third brake lamp bulbs and it still is not working correctly. Any ideas others can think to try? I tried looking in the manual for the blinker relay location so that I could maybe just try and replace that as well but I couldnt find it in the owners manual and I'm guessing they don't look like the good ole big round silver ones anymore. Thanks for any suggestions.

 

Do you have a hitch? Did someone "mess" with the factory trailer wiring? You could crawl under the drivers side rear bumper area and check the trailer connection/wiring to see if this is the culprit, as I'm guessing theres a short in the turn signal light to brake light wiring.

 

No hitch, just the factory 4 plug wiring harness to the back that has not been touched by anyone since I don't tow with this truck.