Tail Light does not work

I need some help...2013 Chevy Avalanche Black Diamond...Tail lights randomly not working. I?ve had it in the local Chevy dealership & of course they were working when they ran diagnostics on it. Driving home one night and pulled over by a cop, rear tail lights not working. Brake lights, hazards, reverse all work...Chevy guys just scratched their heads and said ?bring it back when they aren?t working and leave it for a couple of days? .... any help would be greatly appreciated as I don?t have another $75 bucks for them to accomplish nothing but a labor charge...

Seems other have the same issue. A few things to check, fuses , connectors etc.

this other post may help

http://www.chevyavalanchefanclub.com/cafcna/index.php?topic=59806.0