If you already have the DH 123 ATs, you can still use them. You can cut the leads off the clips intended for the Athearn open frame motor, and hard wire them to the can motors. I have a remotored Athearn unit to which I did exactly that. Wiring to the trucks and frame works the same as in the decoder instructions.
Rob Spangler
Al:
Look at the TCS website. They show the hardwire installation of a decoder in an Athearn Gp38-2 which is the same for the GP40-2. http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/HO_Scale/Athearn/GP38-2/Athearn_GP38-2.html
Joe
You are probably going to have to hard wire a decoder in. Not really the easiest way to go, but it will work. Don't use one that normally would replace a light board, but a generic package like the TCS T1.
http://www.tcsdcc.com/public_html/Customer_Content/Products/Decoders/HO-Scale/KAT-Series/KAT-Series.htm
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
I have a couple of 20 year old (approx) Athearn "bluebox" GP40-2's. I took the shell off of one of them and realized that I had remotored them years ago with "Helix Humper" motors. I realized that I couldn't use the Digitrax DH123AT, or the DH163AT decoders because they use those prewired clips that mount to the top and bottom of the original Athearn motors.There is no provision for mounting them on the Helix motors. Short of replacing them with original motors, is there a fairly easy approach to adding decoders to these locos? They run great with the Helix motors, therefore, I would like to use them in these engines if possible.
Thanks in advance for any suggestions.
-Al