MTH loco problem solved

[jefelectric]

I had an interesting problem with a loco I had not run for a while. A Railking GP9. I set it on a powered track to charge the battery, since it had not been run for probably a year. After charging for a while I started it up and it sounded and ran good, until it came to the first switch & stopped dead. My first thought was a dirty center rail at the switch. Not so, as it stopped dead again as it hit the switch. My next guess was that one of the contact rollers was not making contact for some reason so I checked between rollers and had perfect continuity. After scratching my head for a bit I checked between wheels of the two power trucks, no continuity. After opening it up, I discovered that the screw that holds the black lead to the front truck was loose. I tightened it and everything is back to Normal. This was one problem I had never run into before. Thought I would share it for what it's worth.