Anyone done a P2K GP9?

[JeffShultz]

I've got two Proto2K GP9 locomotives that I'm looking at installing RailPro on - an LM-3S in one and and LM-3 in the other. I think they have Digitrax DH123's plugged into the factory boards on both. Low end Digitrax decoders at least. Most perfectly speed matched locomotives I own.

Personally, I'd like to keep the factory boards, just from an ease of install standpoint.

So if anyone has done this install, I'm wondering how it does on space - particularly will I have room for an ESU 50321 15x11mm speaker without doing any cutting?

Thanks!

[TwinStar]

Jeff:

I have a fleet of GP7's that need RailPro installed but they're on the bench awaiting my passenger fleet to be finished first. Hopefully you can get an answer soon.

[William Brillinger]

I think group member gcarter1945 has done a P2K GP9. Hopefully he will share some of his insights.

( assumptions made based on his post here: https://rpug.pdc.ca/index.php/topic,423.msg3427.html#msg3427 )

[KPack]

Jeff, I don't have any Proto 2000 locos myself, but I have seen the internals.  If I remember correctly they are mostly weight, right?  The Digitrax DH123 is a pretty small decoder.   Depending on the size, the Railpro modules might fit without any other work, but I'm not sure about the speaker.  Do you have a picture of the inside?

I may be a little over the top here, but I almost always remove all the factory electronics and hardwire in a 9-pin harness.  The only time I haven't done that is with a MTH locomotive.  There are two reasons why I do this: 1.) less "failure" points....the more connections you have the more likely it is that electrical continuity will be interrupted, and 2.) way more space inside the shell...I don't like to be stressed trying to make everything fit. 

The first couple of times you hardwire it can be an exercise in patience.  But it quickly becomes routine and doesn't take long. 

-Kevin

[JeffShultz]

The naked GP9.

[William Brillinger]

how long is this space?

[G8B4Life]

I thought I had a couple of DH123D's around here but can only find the empty packets. I was going to take a size comparison shot for you but alas I could only find a TCS T4X that I still have.

The LM-3S measures 38.0mm L x 18.0mm W x 6.45mm H. RE gives you 1.50 x 0.68 x 0.25 Inches in their info. You'd need to add a little bit to the length for "wire return" as the LM has a plug at both ends.

Looking at the board in the photo it appears there is a couple of inductors on the board. I'd be wary of them, the last loco that I tried a module in that had inductors on the board the module didn't like it. Note, that's not just a RailPro thing, many DCC decoders don't like inductors either.

I know you don't want to do it this way but personally I'd toss the factory board. You'd gain a lot of space for the module and possibly a speaker like an iPhone speaker without having to do any weight surgery. You don't even have to solder wire to wire (I absolutely hate that) for hardwiring, a small piece of PCB stripboard makes a nice solder pad if there's room.

- Tim

[JeffShultz]

Well, I can say confidently that it won't fit. So... It is hardwire time. Fortunately I ordered the harness to do that.
Question: does the LM-3 support LEDs directly, or will I need to add resistors?

[Alan]

You will need resistors with LEDs.

[gcarter1945]

If I said I did a Proto 2K GP9, then I was lying like a rug.  However, I did do a Proto 2K GP7.  The only surgery I remember performing was to cut a slot in the nose weight to make room for a modified IP4SK speaker that I bought from Bill.

Picture attached.

Geoff

[KPack]

Nice install.  Very clean.

-Kevin