my 2004 express van 1500 all turn signals work except left rear ,just running light on that side works,good bulb good fuse.

Try moving the bulb in the socket to make contact, have the blinker on so you can tell when it works.

Did anyone find out why the rear turn signal and brake light didn't work? I have the same problem on my box truck,only running light works.tried replacing the whole light assembly only to have the same problem.strange that the light is all in one also.