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RailPro => RailPro Specific Help & Discussion => Topic started by: IDRick on October 10, 2018, 11:53:12 AM

Title: How to hardwire a LM3?
Post by: IDRick on October 10, 2018, 11:53:12 AM

I have two P2K locomotives (GP30 and SW9) and both have factory installed circuit boards.  I may need to hardware the LM3 to both locomotives.  Forgive my newbiness, but I've never actually seen a LM3 so do not completely understand when people "hardware to the LM".  I have three BB athearn and thanks to Chris, I was able to find an excellent video that discussed how to do the hardware installation with 9 wire harness.  However, P2ks are different since they have circuit board and all the wiring is neatly connected to the CB.  I can simply cut the wires at the CB but then how do I connect to the LM3?  Do I remove each initial wire at its solder location to the locomotive then rewire/solder in a 9 pin connector?  Or is there an easier way?

I'm thinking there must be an easier way but I could wrong...  NCE has drop decoders for both locomotives.  In the SW9, the existing circuit board is removed and the existing wires are soldered to the SW9-SR at the appropriate location. The GP30 has two factory installed boards.  The large board is tossed while small one is retained and attached to an 8 pin connector on the NCE P2K-SR decoder.   I would most likely need to remove both boards on the GP 30, correct?

Ian has installed LM3 to a P2KGP30 and will be sending me an image or two.  Thanks Ian!

Can someone provide an image showing the 9 pin connection on the LM3?  It would be very helpful and most appreciated! 

Title: Re: How to hardwire a LM3?
Post by: emd_16645 on October 10, 2018, 12:04:05 PM

if you trace out the wires to the 8 pin connector, you will find that four wires go to the trucks, one for each side.  Two wires go to the motor, and four wires go to the lights.  You can either solder the wires from the harness to the existing wires, or you can break down the mechanism and solder the harness wires directly to each component.  Either way works, its a matter of whatever works for you.  I don't have any photos at the moment, I haven't converted a proto unit yet.

Title: Re: How to hardwire a LM3?
Post by: IDRick on October 10, 2018, 12:23:08 PM

Thanks Chris, you're very helpful my friend!

Title: Re: How to hardwire a LM3?
Post by: emd_16645 on October 10, 2018, 02:15:09 PM

Not a problem!