Try slowly pushing the loco through the Ross crossing with a little power on the track. When you observe a loss of power to the loco, cut the power and tilt the loco over on the wheels on one side to observe the crossing at the pickup. See if you can find exactly on the crossing where the pick up is losing the power. It may be something about the crossing that is causing the loss of power or something with the loco pick up. Repeat several times see what you learn.
I have recently used this method to find out why a caboose pickup got stuck and derailed on one of my Marx switches and was able to add small piece of track pin to eliminate the hang up spot.
Charlie
