My brake lights are not working, but the brake light on the cab is working, the turn signals are working the running lights are working and that hazard lights are working but not the brake lights on the back. I have put new bulbs in them and have checked all the fuses with a fuse tester and they are all fine.I just cant figure out why the two brake lights at the back are not working.
See if the connector is loose or the unit itself is somehow not lined up like its supposed to be.....It may also be Obvious that its broken
Regardless if you can figure out how to test it or not---
IF YOU DECIDE TO CHANGE IT OUT, JUST AS A TEST, TO SEE IF ITS YOUR PROBLEM.......... IT APPEARS TO BE A REALLY "HIGH DOLLAR PART" in the link I'm sending you!