Based on a recent discussion on OGR about most fun operating accessories, I bought a NIB Lionel 22975 Culvert Unloader. I connected it as per directions, and set up a unique engine ID for it (I had the 22965 Culvert Loader and a TMCC loco on the test track as well, all with different IDs). The loco worked as it should, as did the Culvert Loader.
After I initially ran the Unloader and cleared the fully loaded culvert car successfully, I thought I had a working unit. I invited my wife for a show and tell. The Culvert Loader successfully loaded a full set of culverts onto the gondola. When I pulled the train around to unload them, the 22975 unloaded the first 4 pipes perfectly. Then on the fifth pipe the string never retracted after lowering onto the pipe in the gondola (the magnet had grabbed the culvert). It started moving back on the gantry trying to pull the pipe over the side of the gondola. I stopped it, disconnected the culvert, and then tried to move the magnetic hook back and forth on the gantry (with the CAB1-L controller, not by hand), hoping the string retract system would kick in. It never did.
So, before I crack the unit open, does anyone have any words of wisdom?