I have a 2010 Express van, 2500. Extended cargo. For a very long time sometimes my tail lights do not work,and will just come on again. Same for my brake lights. When my brake lights work, my cruise control stops. Right now one right tail light, no brake lights. Top brake lights working. I followed wiring as far as I could from sockets in the rear to front.

 

if you know how to do electrical troubleshooting, there's schematics on gmupfitter.com