I finished up detailing an engine that I previously tested & it showed no problems. Upon re assembling it only runs in reverse on DC. I switched the wires to rule out a bad reversing switch. Still only ran in reverse. The ampmeter moves when it is moving in reverse but doesn't move when it's supposed to be moving forward. Seems like an open circuit. It is a new Mantua with can motor & flywheel. Any suggestions? thanks
I assume that you are saying that the engine moves in reverse no matter which way the polarity switch is thrown? Then it can't be an open circuit. If it were the engine would not move at all.
Do you have a volt meter? Set it to the DC volt scale, attach it across the rails, and see if the voltage goes from plus to minus when you throw the polarity switch.
If the voltage actually switches polarity, then it sounds to me that something is jamming the drive train in the forward direction.
The engine runs in reverse.only when the direction switch is in that direction. When the direction switch is in the forward position the engine does nothing & the amp meter does not move. The motor turns freely in each direction...no binding. there is voltage to the rails, but not to the motor when it' s supposed to be running forward. I'm going to disconnect the factory wiring with the DCC plug & wire it direct.
jerryl The engine runs in reverse.only when the direction switch is in that direction. When the direction switch is in the forward position the engine does nothing & the amp meter does not move. The motor turns freely in each direction...no binding. there is voltage to the rails, but not to the motor when it' s supposed to be running forward. I'm going to disconnect the factory wiring with the DCC plug & wire it direct.
Sorry, I thought that you were describing a straight DC loco. Do you have a "DCC ready loco" with a dummy plug installed in place of the decoder, or do you have a loco with a dual mode decoder that you are trying to run on DC? If either of those cases, someone smarter than I can probably come up with a reason to explain what you are seeing.
Check the orientation of the dummy plug.
Dave
Lackawanna Route of the Phoebe Snow
The orientation of the dummy plug has no effect on loco direction unless you removed it during the detailing and one of the pins is bent over and not making contact.
You need to get a voltmeter and check your track to be sure you direction switch is not defective or improperly wired.
I'd try connecting two wires either to the track (with alligator clips) or directly to the power pack. Open up the engine and try touching the wires directly to the motor leads and see if it works. Then reverse the wires and try again. If it works both directions, then there's something like a diode in the light board that's only allowing power to flow in one direction. As noted, check the dummy plug in the DCC socket to be sure it's installed properly.
KIM that as a last resort you can remove the lightboard and just hardwire everything.
Thanks everyone for your help. The problem is solved. Almost too embarrassed to tell you what happened. this is a new Model power Mantua model with the drawbar /electrical plug combination. Seems like a good idea..but you can shift the plug by 1 pin & it still connects & looks correct. This is what i did & it took a while to figure out.
Really thought I owed it to those that took the time to think about the issue & respond. So many posts leave you up in the air as to if the problem is solved & possibly a solution that could be useful to us...jerry