Mysterious Engine Trouble

[Anonymous]

I am new to building but have been around model railroading for many years. I inherited a small n-guage layout which I disassembled and rebuilt. I also bought a small set new so I had a new transformer and a new engine that would work since the other engines were quite dated.

I tested 2 of the older engines on the new track and managed to get one of them working, although it runs pretty rough. The new engine worked fine, as one would expect. When I redid the layout I tested sections of the track to make sure they were getting power, they were. Oddly enough, the oldest engine runs the track, still rough, but the newest engine barely budges. If I touch the wires to the base of the engine it works fine but when put on the track, it does next to nothing. I set up the oval track that came with the new set and the new engine refused to work on that set too! The old engine works fair on any track I put power to, but the new engine refuses to cooperate anymore, new track or old.

How could an engine NOT work on track when it works if power is put to it and other engine works on the track?? I tested the track in various spots and it gets power throughout the layout.

Anyone expereience this before and have any suggestions? I'd hate to go buy another engine if the problem is not actually with the engine, but it seems very strange.

Help!!

[dknelson]

Well it sounds like we can rule out shorts in the track. What we cannot rule out I guess is a short in the engine -- easy enough to test but where exactly are you touching wires to the engine -- to the motor leads or to the very wheels that are expected to pick up power? There may be a gap somewhere that breaks the circuit from wheel to motor. Try every wheel that is a powered wheel.

Are the wheels clean, including the fillet between flange and wheel surface? Is the track clean?

What size wire are you using to power the rails -- is it too small to give the right amount of current (try bigger wire). Frankly my off hand guess is that perhaps the wire is too small -- it is fine direct to the engine but not enough to power the rail. You may also need more feeders.

Dave Nelson

[Anonymous]

Ahh yes, I think I am learning here, unfortunately by mistake.

When I touch the wires to the base of the engine (is it a magnet?) I get solid power. When I touch the wheels I get a faint glimmer of power, barely worth the effort but it at least tells me it is getting something. Not sure of the size of the wire but I asked at the hobby shop for power lead wire and assume I got the right size.

Now, I appear to be making some rookie mistakes here because when I "serviced" the older engines I oiled them up pretty good and also used some electric cleaning fluid on them. I may have also oiled/cleaned the new engine at one time (can't recall) but I know I have done so since it has been contankerous, thinking that perhaps it didn't like basement conditions and needed loosened up a bit.

So, after taking the engine apart AGAIN and cleaning things as best I could, I get a little more activity from it but not enough to consider it working properly. There are oval copper rings/flanges between the wheels and the base that I assume conduct the electric current from the motor to the wheels. Perhaps I have too much lubricant/cleaner in this area now? Even after cleaning it I still have problems, will it clear up in time or do I need to clean these parts with something different or have I ruined the engine and learned a valuable lesson?

Appreciate the advice thus far.

Scott

[dknelson]

hmmm I wonder if there is a chance that at some point you reversed an insulated wheelset? It might also be that you have effectively insulated what should be a current bearing connection. Keep troubleshooting, I guess.
Dave Nelson

[BRAKIE]

Exactly what brand of locomotives are we talking here..I can help,but need the brand name.

[Anonymous]

The engine is a Bachman Deisel EMD F9.

I certainly appreciate all the help being given.

Scott