I have an 88 B150. Something snapped while trying to open the sliding door. With the access panel removed, I can see that it is the lower rod to the rear latch that is not being moved when the handle is pulled. I can't get any deeper without opening the door, but it won't budge. Any tricks? Suggestions? (besides getting a body with barn doors)

 

Try to get a pair of pliers and pull or push on the rod as a helper tries to use the handle to open the door. Be careful and do not let your hand get pinched while attempting this. Hopefully the problem is in the handle and not at the rear latch.