hi, i have a friend with a 2003 chevy 1500HD quadra-steer LT. the two rear brake lights are not working. the brake light on the cab is functional, and i also get 12v on the trailer brake plug, just nothing on the bed mounted brake lights (bulbs are good, just no power at the sockets). i replaced the
4 plug wiring block mounted on the rear cross-member and it made no difference. i have power going through all my fuses also. before searching for an odd issue somewhere, im hoping someone can suggest any common or known issues. thanks,