EMD GP 40 DIESEL BACHMANN # 41-635-02

[smokingjoker]

Looking for product reference diagram for BACHMANN HO ELECTRIC TRAIN EMD GP 40 DIESEL BACHMANN # 41-635-02.
Engine all of a sudden stoped working I put another engine o tracks it works. If I put the GP 40 on same track with the other engine it stops it like it shorts the track out. Any help thanks

[richg]

Looking for product reference diagram for BACHMANN HO ELECTRIC TRAIN EMD GP 40 DIESEL BACHMANN # 41-635-02.
Engine all of a sudden stoped working I put another engine o tracks it works. If I put the GP 40 on same track with the other engine it stops it like it shorts the track out. Any help thanks

Pull the shell on the problem loco and trouble shoot with a visual and ohm meter. Might be a shorted decoder but most probably a short at one of the trucks. I have heard of some who had a short whem the shell was put on and would disappear when the shell was removed.
Most manufactures don't put wiring diagrams out for their locos.

All DCC locos use the NMRA wiring code, at least for the basic seven wires used to control a loco.

Somewhere the pickups are shorting the DCC signal on the rails.

Rich

[jward]

how old is this loco? is it dcc or traditional dc?

[smokingjoker]

how old is this loco? is it dcc or traditional dc?

Its  traditional from what I could find looks like late 1970

[richg]

My bad. I was thinking DCC.
Below is a diagram of the loco that has the can type motor.

http://www.hoseeker.net/assemblyexplosionbachmann/bachmannemdgp40pg02.jpg

The below is 1990.

http://www.hoseeker.net/assemblyexplosionbachmann/bachmannemdgp40diagram1990.jpg

Two wires. Very simple.

Rich

[jward]

does this one have the solid metal chassis, with both front and rear trucks geared, or is it the one with the plastic chassis and one truck that freewheels?

[jbrock27]

My $$ is on the later.  See Richie's 2nd posted link.  On the schematic page is 2/3 of the above noted model # (41-635).

[smokingjoker]

Got it, it was a bad contact. Thanks

[jbrock27]

Excellent

[jward]

old pancake motored locomotive. low quality. one of the things about these types of locomotives is that if you are not careful when you disassemble them, you can get an axle turned around when you put the truck back together. many older locomotives had pickups on only one side of each wheenset. usually the front truck would pickup off one rail, the rear truck the other rail. if you get the wheelsets turned the wrong way you get a dead short. usually on those types of locomotives one wheel on each axle is plastic and the other metal. if both wheels are metal, one side will have a plastic hub.

[rogertra]

old pancake motored locomotive. low quality. one of the things about these types of locomotives is that if you are not careful when you disassemble them, you can get an axle turned around when you put the truck back together. many older locomotives had pickups on only one side of each wheenset. usually the front truck would pickup off one rail, the rear truck the other rail. if you get the wheelsets turned the wrong way you get a dead short. usually on those types of locomotives one wheel on each axle is plastic and the other metal. if both wheels are metal, one side will have a plastic hub.

Best thing you can do with these older locos is to throw them away.  They are just not worth the hassle of repairing.

They were cheap toy train locomotives designed for cheap department store train sets and only meant to last for a few weeks after Christmas.

Definitely not scale model railroad locomotives.



Cheers

Roger T.

[jbrock27]

By what SmokerJoke said a few posts ago, he solved his problem w/o much ado and w/o looking for additional advice on having to consider replacing what he has.  Make no mistake, I agree that what he has is replacement worthy but that does not appear to be required at this time. 
Nothing more to see here, Keep Calm and Carry On.

[Doneldon]

joker-

Keep in mind that retiring an old locomotive (or whatever) doesn't necessarily mean throwing it away. The body shell, wheels (in or out of their trucks) and detail items can often be recycled or at least used for scenery. Nothing better characterizes railroads than junk sitting around, everything from spikes and tie plates along the right of way to old trucks and body parts in a yard or service area.
                                                                                                            -- D

[richg]

Got it, it was a bad contact. Thanks

Did you get it running?
The reason I am asking is I put a decoder in a Bachmann loco that has the old pancake motor just to prove a point. The pick-ups where not the best but the three pole motor did run quite well. Had to improve the pick-ups. The decoder was only a few dollars.
Motor current was under one amp also. I love to experiment.
Had to isolate the two motor contacts from the frame.

Rich

[jbrock27]

TMI here.