Postwar 2333 F3 Troubleshooting Question

I may suggest that one test the motor independent of everything else.

You can generally operate most any postwar motor directly by following this schematic (ignoring the headlight if you wish)

For the F3 Horizontal Motor, independent test wiring can look like this:

To change direction, swap the leads on the brushes. This will test the motor and if it is good, next places to look are the locomotive wiring, e-unit, the worm shaft bearing orientation etc...

Here is the 2333 wiring diagram. Can you manually turn both motors (via turning the wheels) in both directions - any extra force to get the "bad" motor to manually turn in reverse? If so, could be an armature bearing problem.

The horizontal motors don't backdrive very easily to begin with...

Thanks everyone! I  just got further into it and indeed the problem seems to be a mechanical bind.

I pulled the motor off the truck and its fine in both directions. Now where in the gearbox the bind lies is a conundrum. Are there any common failure points? It seems to bind at one point, but the worm gear drive itself looks fine. the brass block at the end of the worn gear I"m guessing is somehow the culprit

The brass bearings on each end of the worm shaft have an orientation that must be correct for respectable operation. The notch faces up.

Problem solved! I ended up having to open op the whole truck, strip and clean everything with RC car motor cleaner, lube and reassemble. I suspect there was a pebble or other obstruction in all the dirt causing binding.

I appreciate all of your help- another one is back on the tracks!