I got this GP9 and caboose of ebay for $50 (includes shipping) Both are custom painted. 
I am so happy I got this! What decoders for DCC would you recomend for this locomotive?
Depends, who makes the geep?
David B
That looks like a Athearn…Digitraxx DH163AT with easy connect harness for Athearn Blue Box locomotives…Be sure to insulate the motor from the frame-double sided electrical tape will work.
I think the guy is Greg Brewer? And sorry that GP9 is a Athearn.
Greg Brewer? I know a modeler by that name here in Fredericton NB. I can’t see your pics (Photobucket and such are blocked at work), but are those items painted in Maine Central colors?
To insulate the motor on an athearn locomotive as Brakie suggested, You’re going to have to tear it down to the frame and pull the motor. Line the motor support section of the frame with strips of electrical tape and give it a good squirt of silicone. Then, trade the motor’s copper clips around so that the bottom copper clip with the fingers isn’t touching the frame anymore and the top clip is now on the bottom which won’t touch the frame. When you get the decoder, Solder the orange wire to the bottom clip and the gray wire to the top clip before replacing the motor back into the frame housing. Next, solder a wire across both truck pickup clips and solder the decoder’s red wire to it. Next, drill a 2-56 hole into the frame (I always use the thick part of the frame just ahead and to the side of the motor where i drill the hole and mount the screw) install a 2-56 screw, and solder the decoder’s black wire to the screw. The white wire is for the front headlight, the yellow wire is for the rear headlight, and the blue wire is the common return for the lights.
Go to www.tonystrainexchange.com There is an article there that will show you how to insulate the motor from the frame for Athearn locomotives…I like the NCE decoders better than the Digitrax one’s but they are both good decoders. I mount the NCE decoders to the top of the motor using 3M’s double sided tape…chuck
Those are Maine Central colors on both the GP9 and caboose. Thanks for the instructions on the decoder, that is very much appreciated. - Peter