armature testing,need info

You need a low range ohmmeter as the readings will only be a few ohms.  Measure between each adjacent commutator pole and see if all the readings as you go around come close to matching.

Note that this won't tell you if you have a shorted turn as the difference will be too slight.  However, it is a useful test to eliminate other issues.

Also check each commutator segment to the metal shaft of the armature to check for shorts to ground.

Larry

one thing you can check easy is look at the armature under a magnifying glass with a large lens lighted. look specially for a discolored winding around each segment of the armature . if you notice the winding is Black or smells burn you have a shorted winding and as John said you can tell much difference with winding ohms as it will be minor amount of  difference . you look at the field coil and rarely do the field coils over heat but is more common to fail on a armature because they get hot over the years and eventually discolor . normally the copper windings is shiny and looks sort of like gold or shiny but when the winding have been very hot the copper turns black! when it has turned very dark the insulation breaks down and can short against other windings on top of the layers of winding!

Alan    

There are many different types of the 1001M-23 armature differing in wire gauge, length, turns, and resistance measuring between 1.2 and 3.0 Ohms.

Set your multimeter to ohms and then test each combination of the 3 commutator faces. The reading should be essentially the same (and somewhere between 1.2 and 3.0 ohms).

In other words, the measurements of A to B, A to C and B to C should all be about the same and within spec.

Then test A to Shaft, B to Shaft, and C to Shaft. All of those should be essentially infinite Ohms (no continuity).

This procedure can be used on most any Lionel armature, however, the specific expected ohm reading varies from model to model.

Thanks guys.....problem solved,burnt field coil..grateful  for the info....joe

Ah ha, looking in the wrong place!

You might be able to rewind that yourself if you're energetic.

Just as with the armatures, there are a few types of fields... They use either 25 or 26 wire and 175 to 250 turns.