i have a 2012 chevy express van the turn signal brake light and tail light all in one bulb everthing works except tail light socket good fuse good bulb new weird?

Just check the left side bulb, sometimes the element breaks off when handling and you wont know it because the glass is clear, shows no sine that it is burnt. Also some times you just have to work the bulb in the socked to make it make contact.

There was a change between the 2011 and 12 . They discontinued the use of a brake light switch and went to a brake pedal position sensor. The brake pedal still has a mounting knob on the upper left shafts of te pedal that will a hole in the main wiring loom that enters through the fire wall when the pedal is depressed. Benet the point of contact in the loom is the left tail light wire. When the pedal is depressed and the left turn signal activated it will short. Check tgere and the fuse fir damage

chevrolet express 2010 2500.left signal and brake light not working I changed the light bulb and fuse and still not working please help