The colors on the DECODER side are a standard, however locos can be anything. On the newer P2K locos (newer being relative - those GP-7's of mine are 9 years old) they use that same color coding for the loco wiring, as do some other brands. But some use all oen color wire, or even colored wire that doesn't match the NMRA DCC RP. So you may have to do a little digging to verify that yes, this black wire goes to the bottom motor contact, and this one goes to the right side of the lead truck.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
It's not rocket science. If you need to hardwire the decoder in, which may be necessary, if there isn't enough clearance for the plug in, the red and black wires go to the right and left track pickups. The grey and orange wires go to the motor leads. The blue wire is the common wire for both the front and rear lights. The white wire is the headlight, and the yellow wire is the rear light. I believe these wire colors are standard for all decoders.
If it's a newer one like that pictured on the TCS site, take a look at the install pictures on my web site. Actually, I also have pictures of an SD7 as well, which was an older P2K model that did nt have an easy drop on decoder option, so you can see both ways. For the GP7, if it's a newer one like mine, the Digitrax DH165L0 decoder is a super simple drop in replacement and you don't even have to change the bulbs out. It will take longer to get the shell off than to install this decoder.
Not the greatest picture, but this was quite some time ago and I only had a rather poor quality cheap digital camera:
Try this. If it is an older one, other instructions would apply, but the GP7 is most likely a newer, easier one to deal with.
Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com
Check youtube - I think there's quite a few very helpful videos there for newbie installers like us.
I've just gotten my system working and my mainline running with a Super Chief II Digitrax setup with a converted duplex throttle. All seems to be working fine. I am now ready to tackle converting a Life Like Proto 2000 GP 7 to DCC. On some good advice from a DCC guru out west (you probably know who I'm talking about) I ordered the parts from them and am waiting for those to come. In the meantime, I'm garnering as much info as I can being that I have no idea what I am doing. So any good tips in general that you can share with a complete newbie in this arena would be appreciated. I guess my main concern is that I don't know the general setup when it comes to the wiring in one of these locos. Thanks!
Michael E. Maurer