imgsrc="http://www.bluemountainaerialmapping.com/track.JPG" The gaps are the red lines. I am using MRC Prodigy Express and MRC reversing units. I get a short or "svda" on my menu on the cab when the engine passes over one of the gaps. It happens in each loop. I have tested it running just one engine with no cars with the same result. I believe I have the reversing units wired good. Let's go from there...any thoughts? Thanks. RL = reverse loop. The rest of the track is wired common rail.