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       #Post#: 1243--------------------------------------------------
       Prewar Lionel 153 Locomotive Shorted
       By: jsonova99 Date: January 3, 2016, 7:38 am
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       So I just bought an old prewar set with a 153 locomotive.
       Everything moves freely, but it appears that everything is
       shorted to ground.  It has the 2-position reverse switch but
       I've ruled that out as a problem by bypassing it and having the
       same issue.  Anyway, here is what I have so far:
       1) All three commutator plates measure about 1-2 ohms (as I
       recall) between each other, and none are shorted to the armature
       shaft.  That should be signs of a good armature as I understand
       it.  Brushes are worn but serviceable and I do get good
       continuity measurements of an ohm or less from brush to
       commutator.  These are the old soldered in brushes.
       2) I have rewired the engine, it's wired right, but because the
       wiring was so brittle, I didn't do any troubleshooting until
       after I rewired, so not sure if it was there originally or not.
       3) The short appears to be the field winding, but the field is
       connected to ground at one end, so I'm not sure that is wrong.
       It's just a coil of wire that runs from the brush to ground, so
       I would expect to read a near short from one end to chassis.  If
       I disconnect the field at the switch, then there are no shorts
       to chassis of the commutator, pickups, or brushes, but as soon
       as I connect the field, everything is shorted.  I have another
       prewar engine that I'm going to try probing to see where the two
       differ, but I'd love to get some thoughts from others on this.
       Forgot to add that it does try to move in forward and reverse
       when switched as it should, but it overloads the transformer
       almost immediately due to the short.  Found this before I
       started taking resistance measurements to verify the short.
       Thanks in advance!
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