"They used to but no longer do (Gargraves turnouts with continuity on all three ends). That was done so you can have an isolated section or siding without having to cut the connections between the third rails"
Glad you figured it out. I am surprised the transformer did not trip and shut down.
You should still consider the ground on the opposite rail (alternate ground connections along the track). This way both sides of the track are hardwired to ground and you don't need to depend on the truck wheels to make a good electrical connection.
