# AHM/Rivarossi 0-8-0 motor/wire issues



## trainguru (Jun 28, 2011)

Does anybody have the wiring diagram for the cab motor 0-8-0, with the driveshaft. Any help on fixing it what so ever? I got it for $6, and I'm trying tomake it work better. Any help is welcome, thanks and God bless.


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## shaygetz (Sep 23, 2007)

http://hoseeker.org/ahminstructions.html


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## trainguru (Jun 28, 2011)

This kind of helps, but it doesn't quite explain the wiring...


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## Massey (Apr 16, 2011)

what exactly do you need? Wiring on these engines is usually really simple and only a matter of pickups from the wheels going to the motor and headlight. Middle to high end engines usually have a printed circuit board that can switch the headlight front or rear depending on the direction the engine is traveling. They can also add a DCC quick plug for easy DCC installation. If you need I could prolly draw you a generic schematic of the typical DC engine.

Massey


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## Massey (Apr 16, 2011)

I was just thinking about the pinouts for the tender to cab plug. Do you need this information? If so you could find out what goes where with a multi-meter. Or you could contact the manufacturer and see if they can send you some documents on the engine.

Massey


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## T-Man (May 16, 2008)

The motor needs two wires, one from each rail. The tender drawbar is a ground to a truck and one rail. The otherside of the tender axle is isolated and picked up with the wire that is fed to the motor. WIthout seeing the tender this is the best I can do. Each truck may be a separate feed too. Just look closely at the tender and it's axles.


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## Massey (Apr 16, 2011)

OK I used good ol' windows paint for creating a few schematics of basic locomotive wiring. If you want I can create one that has a DCC plug and the correct DCC wiring color codes.

This is one way to create directional lighting. If there are LEDs there may be resistors in there as well. 










This image is just a basic DC wired loco with all wheel pickups and a plug between the tender and loco. 










Massey


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## T-Man (May 16, 2008)

Do you have one of these? I have the latter version and I find the drive wheels are isolated from the rails. So one side would be connected to the frame, otherwise a great paint diagram!

I checked on my later model the drive wheels on the left and the right tender wheels supply the rail power. 

I think the draw bar is isolated from the frame so the tender power goes through the drawbar to the motor. Then the frame and left drive wheels do the rest. The left drive wheels are wide in the back and connect to the frame with a spring loaded pin.

To be clear I have the center motor model, you have the 1972 version.

I have a drawbar you have a pin from the tender that rests in the frame.

You should know what to look for now.

With the drawbar or pin supplying power from the tender no wires are seen going to the cab.


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## trainguru (Jun 28, 2011)

Could you show photos of your later model's mechanics, so I can see what the equivelents are, T-Man? And there are no directional lighting, no DCC, and all I want is to run the locomotive proper, for further references. I purchased the locomotive, with the intention for operations on my pike. and I am trying to solve this problem. Lighting is an issue for later, but the diagrams may help. Thanks Massey! God bless all who have helped so far and later on!


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## T-Man (May 16, 2008)

Ok pictures. Rivarossi uses a blue metal disc to jump a connection from the outer wheel to the axle. The tender left wheels have this at the top of the picture. Both trucks have the same contact and are attached to the tender post. The draw bar crosses to the engine to an isolated rivet and then directly to the motor brush











This shows the drawbar, rivet and wire to the motor.










Here you see the right drive wheels with the disc









The drive wheels are attached to a frame piece to a metal link to the other brush to complete the connection.










Here is a link to the other thread.


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## trainguru (Jun 28, 2011)

Thanks, this gives me some idea about the older one!


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## T-Man (May 16, 2008)

*Hot on the subject.*

So this spring connects the axle to the frame and the brush.











This hole using a screw connects to a wire and the bulb to complete a light circuit.The weight is a different polarity from the frame. 










This shows an isolated connection from the tender. It connects to the weight holding the light. .


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## T-Man (May 16, 2008)

*1972 version*

I do have the 1972 version. I used the parts to explain everything but when I got the engine I remembered. 


So the light is powered from the right drive wheels to the frame to a screw and nut just below the bulb and wired to it. The weight is grounded by a clip attached to the brush by a wire and goes to the tender by the isolated drawbar.




















The wire from the clip to the brush. The drawbar is isolated from the frame and a wire on top, and under the motor goes to the brush.









This shows the other brush grounded to the frame.










WHAT EVER YOU DO, DO NOT DISMANTLE THE MOTOR. It has small bearings and it is imposssible to reassemble with the magnets etc. Leave it alone.

To remove the body remove the two forward screws in the back and the main screw in the front.










Slide the shell forward.










If you get it going, this is it.


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## trainguru (Jun 28, 2011)

Thanks, this is very helpful!


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## NIMT (Jan 6, 2011)

T-man is extremely full of knowledge and very helpfully. 
You'll find that there are a lot of people that will help and give some great advice too!


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