third break and turn signal issues

[Red3.slow]

So today I got the quick clicking of a turn signal being out, and my third break light has been out since i bought the truck. When I go to replace both of the bulbs I find that they aren't blown. I manage to get the turn signal to come on for a little while but as soon as I drive it, it goes out (loose wire or bad socket I'm assuming). How ever I'm completely stumped on why the third break light isn't working.

Anyone had something similar happen, any ideas on what I should do.