The installation is for HO Scale Bachmann EMD DD40AX . It uses TCS T4XP-SH digital decoder and was performed by a A.G.
The three pictures above show the Bachmann EMD DD40AX prior to the TCS T4XP-SH installation.
Using phillips screw driver, remove the front screw of the oil tank.
Using phillips screw driver, remove the rear screw of the oil tank.
Using phillips screw driver, remove the front copuler pocket.
Using phillips screw driver, remove the rear coupler pocket.
The four circled in red screws holds the chassis together with the shell. They all need to be removed prior to the decoder installation.
Here is a picture of the original light board after the shell removal. The original Bachmann decoder can be seen between the motors in black shrink wrap.
Here is a close up of the Bachmann decoder.
Remove the original 8PIN plug together with the Bachmann decoder.
The picture above shows the chassis with the Bachmann decoder removed.
Plug our T4XP-SH decoder into the 8PIN NMRA socket so that pin #1 is lined up with the orange wire.
Another picture of completed T4XP-SH installation. Black electrical tape was used to fix the decoder to the chassis.
The picture above shows completed TCS T4XP-SH decoder installation.