This installation of TCS DP2X Decoder is for HO Scale Athearn AC4400 and was performed by A.G.
The three upper pictures show the beautiful Athearn AC4400 with its shell on prior to the DP2X Decoder Installation.
Unscrew the front screw (circled in red) that holds the coupler pocket to the chassis and remove the front coupler pocket.
Unscrew the rear screw (circled in red) that holds the coupler pocket to the chassis and remove the rear coupler pocket.
Grasping the shell by the solid area between the grills, lift the shell straight up and off of the chassis. Be careful not to break the wires for the lights. If you decide to use the 8-PIN NMRA socket, make sure you remove the plug that is marked in red. If you install the DP2X witout prior JST plug removal, you will damage the decoder.
JST Plug removed.
Plug our DP2X decoder as shown in the picture above. Hold the shell in one hand and the chassis in your other hand. Lining up the front of both pieces, lower the shell onto the chassis, keeping the lower edge of the shell parallel with the chassis. Do not forget to attach both couplers.