I have a 1999 Ford F-250 super duty XLT with a V10 Triton gas motor. With a four door cab that sometimes the rear door won't open. The latch with move and work like they should but the latch on the inside of the door won't release opening the door. If I give the latch that senses the front door is open a few times its sometimes opens. I would like to know whats going on on the inside so I can figure out a way to repair this?