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My antenna is off a 55/56 model (12v). I had to fabricate a bottom mount for it as the style of mounting is different that the 51-54 unit. See blog for more info.

I remember now and forgot you had converted. 12v is probably why the capacitor. So it seems the main difference is the elimination of the circuit breaker and ground arrangement in the 6v. As long as the ground is making a good connection to bat on the bad one, then a continuity check should point to why no sign of action at all. Even if something shorted, there should be a spark or grunt.

Reference Post #283 - This is what I have done to run the tests suggested by HH56. Here is the first one:

"Place one meter lead on the terminal where one brush attaches to the two coil leads. With the meter on ohms, use the other probe to touch the metal support and make sure a coil isn't shorted. If good there, then connect to each of the harness wire leads in turn. Each should read a short there since there is no resistance to speak of in those coils."

I put my multimeter on OHMS and put one lead on the brush connected to the two wires going down to the coil (blue dot in picture). Next I probed all of the dots shown. Green dots indicate a good connection. The red dots showed no movement on my multimeter (no connection). I also tested the harness wires. They both had a good connection. The ground wire did not, but that is because it is not hooked up to anything right now.

On the bottom coil, I noticed no connection when touching the bottom wires. The top three show a connection. Could that be the problem or perhaps the outside coating on those wires got rubbed off during the cleaning process.

Any of this mean anything?

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Here is the other part of the tests.

"With the meter still connected to the coil and brush terminal, check for a shorted armature winding by touching the probe to the steel in armature--both the shaft and the outer part. If good, then connect the other meter lead to the other brush and check continuity as the armature is rotated in the brushes."

Green dots are good connections. I also put one test probe on each brush and turned the armature and it showed a good connection for the complete revolution.

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.....check for a shorted armature winding....

EACH segment of the armature should be checked for a short, just as you'd do when checking a generator or starter armature.

Sorry I should have mentioned that. I put the green dot on one of the armatures to show it was done, but I should have wrote that I probed each one. I also probed each segment of the commutator.

By the way, I have never checked a starter or generator. All of this stuff is very new for me!

You may be getting some feedback thru the other brush and armature because I tried to be brief again, skipped something and didn't have you isolate the armature for the first check. I had you put the armature back in the third paragraph but never had you take it out in the first place. Forget not everyone does this daily and didn't mention one of the important steps. My apologies.

Put a piece of paper between the brushes and armature or pull them away first. Now with the meter on ohms, and the probe connected at blue dot, you should not see any movement (infinity or open) anywhere except the two leads at the end of the harness cable. At the two wires, there should be 0-1 ohm or essentially a direct short.

After that, keep the paper there so the brushes don't connect but touch the commutator with one probe and the steel on the armature with the other. Do as O_D mentions and check each segment of the commutator to armature steel. The meter should not move ie no connection or infinity. Then do segment to adjacent segment. There will be some tied together and I don't know the spacing. Opposite sides where each brush would connect, yes but I don't think next to each other. If there is an adjacent connection, have to work out the overlap path and that would need a motor person. Do opposite each other next and there should be a short or very low reading. Rotate the armature and check the next pair, rotate and the next etc etc. If all good, then remove the paper and do the rest of the checks.

Connect everything up, one lead to ground the other lead to each of the harness wires individually. You should have a short or very low ohms. Rotate the armature and you should have no or very minimal flicker of meter movement -- it should stay shorted. If all those check good, then there is continuity, no shorts and the motor should run. If not then it's time for an electrical person for expertise .

No reason to apologize HH56...your help has been invaluable. The results of the first test were good:

"Put a piece of paper between the brushes and armature or pull them away first. Now with the meter on ohms, and the probe connected at blue dot, you should not see any movement (infinity or open) anywhere except the two leads at the end of the harness cable. At the two wires, there should be 0-1 ohm or essentially a direct short."

Added the paper between the brushes. I did not get a "short" touching anything but the two wire leads and the bottom coil of wire (the one the brush it hooked up to anyway).

If I did this correctly, second set of tests were also good:

"After that, keep the paper there so the brushes don't connect but touch the commutator with one probe and the steel on the armature with the other. Do as O_D mentions and check each segment of the commutator to armature steel. The meter should not move ie no connection or infinity."

Put one probe on commutator segment and the other and the armature steel directly below it. I got a couple of "short" readings, but realized the motor had moved and was hitting the electromagnet frame. Once I kept them from touching, no shorts.

I also connected a probe to each commutator and to the shaft. Not sure if that tells anything, but no shorts either.

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OK...next set of tests are not so good. I tested commutator segment to adjacent segment and got a short. Checked opposite segments and got a short. Checked every other segment and got a short. Seems like they are all tied together. Thought maybe I was having the same problem with the armature touching the electromagnet housing so I added paper between them and that did not help. Did I do the test wrong?

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