We have a 2004 (late year) Marquis with 4 slides. We've had the bedside slide fixed so far and now the opposite side rear slide is hanging up when operating the slide. The motor which sounds like it is on the rear side of the slide seems to bind and the slide hangs in the front side so the slide is attempting to open at an angle. If provided some foot pressure at the floor level, it will open. Clearly not right, have never had problems with it before. Is this an adjustment problem or is there a sissor link problem. How does one get to the mechanism to adjust it?