93 Pathfinder lock won't lock

My 93 Pathfinder recently developed a problem : my locks won't lock manually, by remote or by key from outside. When I use the remote I hear a noise from drivers side rear and the security light flashes but locks don't do anything , Help !

I found the problem, there was an exposed wire (insulation worn off) under the switch panel on drivers door. Shorted out the "power door timer" $99.00 at nissan. I don't care that much about power locks so I disconected the timer, now I have manual locks, Problem Solved !