I’m trying to troubleshoot a Lionel No. 624 Chesapeake & Ohio NW2 diesel switcher from the 1950s. The motor seems to short out, even after I spent time cleaning out the dried grease from long ago. All I get now is a grinding noise, and the locomotive barely moves. What do you think is the problem? — Tom Rivers
I’d start by disconnecting all the wiring between the E-unit and the motor. Then try the motor with a set of test leads from your transformer and a jumper wire. Connect the ground lead to the motor frame and the hot wire to one of the brushes; then take the jumper lead and connect the field to the other brush. If there’s a short, you’ll know the problem lies with the motor. You should next look for a bare section of wire on either the field or the armature. If the motor runs without a problem, the E-unit or the wiring between it and the motor may be the culprit. In that case, I suggest you look for damaged wiring or parts in the E-unit itself. Then replace whatever you find is broken.
