# DCC Proto 2000 GP9 to Railpro LM-3S upgrade- What is the ground wire on the weight?



## SRV1 (Nov 14, 2010)

Hey all. It's been a few years since I've installed a Railpro module but have never had an issue. This Proto 2000 GP9 from 2001 came in and I cleared out the circuit board and bulbs. Hardwired the LM-3S into it and my HC-2 controller is not finding the new hardware installed on the loco. My question isn't about the LM-3 specifically. I don't know why it's not seeing the module but my main question is what was the short little black wire that went under a screw on the weight? Like a ground. It went to the circuit board. There's not a place for it to go on the LM-3S module. It said it's a DCC model on the box.

If anyone has any ideas, I'd be interested to know. I soldered one LED in for testing. Speaker is attached. I took the voltmeter and was able to measure voltage on the pickups above the trucks so the power is going up to the wires. I sent the black wire to one truck and the red wire to the other truck. I don't know if it matters. The power pack light will go red if there's a short and it's staying green.


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## DonR (Oct 18, 2012)

With DCC it doesn't matter what rail feeds the red wire...

Since you have checked the Red and Black wires from
the Trucks...have you checked that they are actually connected
to the decoder input? I have no knowledge of
your mysterious black wire screwed to the frame unless
you are working with a split frame electric system.
Perhaps someone with experience on the Proto GP9
can answer your question.

Don


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## SRV1 (Nov 14, 2010)

The wires go directly into the harness that plugs into the LM-3S module. It's a small rectangular pack/receiver that controls the locomotive wirelessly from the handheld. There's no board installed now. The wires from the harness just solder to the locomotive's wires.


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## DonR (Oct 18, 2012)

Is the DCC decoder still installed? If so, it may not be
set for DC. Otherwise no knowledge of Railpro.

Don


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## SRV1 (Nov 14, 2010)

DonR said:


> Is the DCC decoder still installed? If so, it may not be
> set for DC. Otherwise no knowledge of Railpro.
> 
> Don



I just solved the problem based off of customer support. I've never had a Proto model before. No there's no decoder or any circuit board whatsoever left on the model. Picture just wires going to a 9 pin wiring harness that plugs into a little rectangular blue and white module. That's it. That is the receiver that runs the engine from wireless touchscreen controller. Really easy to set up and load custom sound files into it over the air. Can run on any DCC powered layout but receives info wirelessly through the air instead of through the rails.


The issue was that the two wires, one coming off of each truck are picking up current from only one rail. The metal "weight" that takes up the entire interior of the body is electrified! Its picking up power from the other side of the trucks. That's why the wire was screwed to it. It was a power wire. So I'll have to be extra careful the legs of my LEDs aren't exposed on that thing. Space is really limited in it.

Here's a pic of the project. I drew up and 3D printed the box for the speaker. It fits perfect in the shell. The entire silver frame has power running through it. I don't know that I'm a fan of that but it is what it is.


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## Ron045 (Feb 11, 2016)

Wow... There are other RailPro people here? I would not have guessed that.


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## SRV1 (Nov 14, 2010)

Ron045 said:


> Wow... There are other RailPro people here? I would not have guessed that.


 Yeah, here I am. I got it back in 2017 or so. Did 5 installs then kind of took a break for a while. I do detailing and weathering. I got the itch to do one of these GP9s. Just installed the ULT prime mover file, horn and bell last night. I found out about railpro back in 2014. I figured more people would have converted by now. I don't love installing them into the tight spaces with speakers but once you do it, the final product blows away DCC capabilities. Probably not a lot of people out there who want to put the time into the installs. They just want to take stuff out of the box and run it. I can't blame them but if that's the case, railpro coverage will be limited for quite a while. I leave DCC in my old steam engines since its antiquated technology at this point.


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