93' F-150 Tailight Not Working

Ok, all of my lights work except for the driver's side tailight, the headlights and the passenger tail light all work fine, also the driver's side rear brake light works, its only the running tail light that doesnt work. I have put new bulbs in both tail lights and a new socket for the one that doesnt work but it still doesnt work. I havent checked fuses (didnt think a fuse would work just one tail light and not both). I read somewhere theres a disconnect on that side, but wouldnt that disconnect all the rear lights? or are there individual ones? I also didnt check the light switch, figured if that was bad then all the lights wouldnt work, or atleast like all the rear or all the front, not just one tail light. Any ideas?

check for a broke ground wire,ford used to be bad about the ground strap inside the socket corroding also corroding in connectors.get a continuity checker or multimeter and just keep checking everything backwards from the bulb.

Alright, ill try that tomorrow, im hoping thats all it is.