Athearn SD40 T1 Decoder Installation

Installation performed by an anonymous source

Although the SD40 comes with four 1.5v bulbs, they were replaced with LEDs for long term reliability. After removing the 2 bulbs in both the front and rear lites, Details West plastic lens are inserted into the lite openings. Then short lengths of wire are soldered to a pair of 3mm Sunny White LEDs. The LEDs are then covered with shrink tubing. The LED for the front lite is inserted into the opening in the cab roof. In addition quick connectors are solder onto the ends of the wires to facilitate the body shell installation / removal. See Fig. 1.


The LED for the rear lite is inserted in the groove in the rear weight. This lines it up perfectly with the rear lite casting.

See Fig. 2. Not shown is the rear "light shield" made for black styrene that was glued to the top of weight to prevent light leakage thru the fan castings.

At this point the SD40 is ready for installation of the T1X. See Fig. 3. Notice the pair of quick connects for the front hear lite LED.

The wires are tucked neatly into the body shell and the shell installed on the frame. Here's a photo of the completed loco after detailing.