Decoder for 1st run Proto2000 HO GP18

[Cannoli]

I apologize if this is a duplicate post, I did search the forums first but couldn't find anything. I have a Proto2000 HO B&M GP18 that has been sitting in it's box for quite some time. I have been planning on converting it to DCC, just haven't taken the time to do so.

Has anyone installed a decoder in one of these locos? If so which did you use? I'm not looking for sound, just basic 4 digit addressing and light functions.

Thanks,

Jason

[jamnest]

I have done the same installation.  Hardwire with a Digitrax DH123 decoder.  It is easy to do.

JIM

[Cannoli]

Thanks for the tips, I do have a couple of DH123D's handy so I'll make it a project for this coming weekend. My fear was whether I would need to cut into the weight at all in the loco but it doesn't like like that's required.

Thanks,

Jason

[bandmjim]

  I too am thinking of installing a decoder into a couple of these, so a timely post.  My question is what if any problem with motor isolation, and lighting, any problems there. Anything special that needs to be done or just a straight install.   Thanks for your help.  Jim

[Arjay1969]

The nice thing about Proto 2000 locos is the fact that the electrical connections are all hardwired, and are completely isolated from the frame.  That makes decoder installation a LOT easier.  On the early ones, though...they didn't have decoder plugs, so hardwiring is the only option for those (early meaning from the original BL-2's up through the first runs of the GP-20's, and I've heard tales of GP-7's with no decoder plugs, but haven't actually seen them for myself).

Oh, and watch out for the bulbs...LL tended to use 1.5v bulbs for its headlights rather than 12v.  That's good as far as heat, because the 1.5v bulbs won't melt the shell.  It just means you'll either have to install resistors or use the TCS A6X decoder which has a 1.5v voltage regulator built in for lighting functions. 

[Cannoli]

I've never used the TCS A6X decoder before, I like the idea of it being prewired for lighting with resistors. Will it fit into the first release GP18's since it would have to be hardwired in?

Thanks,

Jason 

[Arjay1969]

More than likely, the A6X will fit even better than the DH123, since the A6X is a bare board, and is REALLY thin.  All you'd have to do is take out the original board and replace it with the decoder.  I'm assuming the board is the same size as is standard now...I don't have a GP-18 to look at (Santa Fe didn't own any! ), so I can't confirm that.

Good luck! 

[jfallon]

    If this is really a first run P2K GP18, I don't think there is room for a DH series decoder. These locomotives predated DCC. There was no circuit board in them, just a diode bundle for the directional lighting. I have hardwired in a Digitrax DZ123 decoder into one without much trouble. If you remove the diode bundle the decoder can just fit into its space. Remember to sweitch out the lamps with ones rated for 12v.                    John