Guys, I’m having a real brain stall tonight. I have an older Athearn GP38, but awhile back installed a new NWSL “can” motor (replacing the original motor and clip). The can motor has two connections…one positive (near the bottom) and one negative (upper). I had installed a decoder early on, but have had stalling issues with it and now want to test this engine again only on standard DC currrent to make sure it is not the can motor or gear drive. I forgot how to re-wire this. Could someone please send me the simple wiring instructions (or diagram)? Thanks. John
Analog DC - locomotive* moves forward with positive power on right-hand rail as seen from the engineer’s seat. Design of the motor has nothing to do with it.
Since I’m not familiar with the power pickup arrangement of your particular locomotive I don’t know you would connect the motor to the wheels or wipers. I’m sure that a few minutes with a mutimeter would establish the pickup continuity and rail polarity.
If the loco runs in reverse with positive power to the right hand rail, just reverse the brush connections.
- “Locomotive” includes DMU and EMU cars, or anything else self-propelled.
Chuck (Modeling Central Japan in September, 1964 - analog DC, MZL system)
I see where you mentioned you installed a decoder but no mention of you isolating the motor form the chassis? I am not the go to guy with dcc but as far as wiring the dc motor it should be pretty straight forward. I found this diagram from an NMRA site that tell you how to tune up your Athearn
http://www.mcor-nmra.org/Publications/Articles/Athearn_TuneUp.html
To run the motor on DC you will need to disconnect the decoder from the motor first. Leaving it connected for the test will fry the decoder.
After disconnecting the decoder, just connect one motor tab to one DC lead. Connect the other lead to the second motor tab. That could be as simple as just connecting some wires from a DC pack to the motor or connecting each lead to the rail pick up one one side. There is no actual positive or negative contact on the motor. + and - get swapped every time you change direction.
Martin Myers
Most decoders will allow you to run on DC. Just make sure it’s enabled in CV29.
Just DO NOT apply DC to the motor terminals with the decoder hooked up, that WILL fry the decoder. But assuming the decoder has CV29 set to allow analog conversion, just apply DC to the wheels and it would run. If wired with standard colors, and you want to remvoe and bypass the decoder, orange from the motor + goes to red from the rails, and grey from the motor - goes to black from the rails.
–Randy