I recently purchased a Marklin 3023 online. The challenge -- lights work, reversing unit cycles, but no movement of the locomotive or armature. It is a beautiful locomotive, and I hope to get it running soon.

Here is what I have done to troubleshoot the problem:
- Thorough cleaning of all gears and the armature. With the brushes removed, everything spins very easily. No armature rotation.
- Replaced brushes and eased the tension a bit on the brush springs. No armature rotation.
- Confirmed track voltage present at brushes with a voltmeter. No armature rotation.
- Put the suspect armature in a 3021 locomotive; both share the same 800 style armature. The armature rotated and the 3021 locomotive moved as expected.
After successfully testing the 3023 armature in the 3021, I started looking elsewhere.

At this point, I'm suspecting the field magnet. To check:
- I placed a paper clip on the iron plates with track voltage applied to the locomotive. No evidence of a magnetic field.
- To confirm that test method, I did the same with the 3021 locomotive and the paper clip was definitely attracted to the iron plates and actually stayed perpendicular to the plates.

Before I search for a 20287 field magnet, can anyone suggest troubleshooting steps I may have overlooked?

Best regards,
Pat

Mikey, thanks for that idea. Let's pretend that I interpreted your advice correctly. Below outlines what I did to check resistance through the field.

I placed multimeter leads at the points shown in the diagram from service manual, where the field magnet red and black wires are soldered into the reversing solenoid:



I measured resistance with multimeter across those points with no track voltage -- about 3 ohms. I then increased track voltage to about 7 volts and measured again -- again, 3 ohms (essentially no change).

As always, any feedback from forum members is appreciated.

Pat

Let me start with the good news: all is well with the locomotive! It runs in forward and reverse, using either track or catenary as power source.

What happened?

When I received the locomotive, lights and reversing unit were functioning, but the locomotive did not move. I removed the shell and the brushes to determine if gears were gummed up with old lubricant. Yes, the gears were very hard to turn, so I cleaned with lighter fluid and everything turned freely. I took the opportunity to lubricate the armature sponges and replace the worn brushes. However, when track voltage was applied, nothing moved. Please note: I did all of the troubleshooting outlined in my first post with the shell removed.

When I read Rudi's note, I wanted to confirm what I had seen earlier. I placed the shell back on the chassis, installed the lights, and tested the reverser and lights. To my surprise, the locomotive started moving smoothly and quietly down the track. I was very happy.

What did I learn?

The 3023 does not operate without the shell and light bulbs in place. Perhaps other Marklin electric locomotives of that era with lights that switch over to match direction are the same?

My thanks to Mikey and Rudi for asking the right questions.

I agree, the locomotive should run without the body and lights installed. Is it possible that the tabs for the lights are touching the chassis and shorting out.

Hello Pat,
There are 2 windings on the field. One for forward and the other for reverse. In order to check ohms correctly you must isolate the winding completely (unsolder) and use no voltage. Perhaps this can be helpful in the future.
Mikey

I was watching that auction too. That is a very nice locomotive you have, especially with the box being in excellent condition.