My '86 F150 just decided this morning to not let me in the bed. The left side will release but nothing on the right side. Any suggestions would greatly be appreciated.

 

Look up under the pull handle. The ends of the left and right latch rods are connected to the pivot plate by a snap in plastic bushing / clip. The clips tend to break and the rod(s) will fall out of the plate. The clips are not very expensive even at a Ford dealer.

 

Just use a flat blade or pry bar to push the catch down. Mine does this often.

 

My '84 has the same problem. I just pull the handle with one hand to release the right side, then reach underneath and pull the left latch rod with the other hand. (This works for me since i don't actually open the tailgate that much anymore) but i would go ahead and get the plastic clip if you use your tailgate very often.