I have been asking around about this here and decided to just give it its own thread. I need to install a decoder in my SD9, since there is no major difference and the SD9 is in the diesel shop for a total overhaul, I figured I could use a GP50 to ask questions (I will not actually give it a decoder yet). I do not have the actual decoder, but I do have all of the wireing, and if I understand I could install the wires and than buy the decoder and just plug it in. I will be giving the SD9 (and later the GP50 in guage railway leasing colors from which the DMIR recieves temporary motive power) a Digitrax DH126AT decoder. I have been told I need to insulate the motor from the frame. I was looking at the GP50 and found a metal strip below the motor embeded in the frame. Is this what I need to insulate from the motor and if so how. This is all I want to know for now, I would like to go at this one step at a time so I can follow. Thanks for any help, and sorry for the reading, hopefully the rest of the posts will be shorter, I can also take pics as I go to make sure I am doing it correctly, but so far this is my longest post so I feel like I can stop anytime now.