I have a C-607 Caboose that only lights intermittently. The lamps are not burned out . If I put a multi meter on the 3rd rail and touch the pickups the lamps light up. All the connections are tight - no loose wires. This is a new caboose. What is going on? My Williams and Lionel loco's run fine. The transformer is a Lionel CW-80 which powers old-style Lionel track. The both loco's head and cabin lights light up fine when running. I'm am puzzled as to what is going on.