This installation is for Athearn SD40 uses TCS T1 decoder and was performed by TCS Customer.
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 TCS T1 decoder . 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.
Important Soldering Tip
Please do not use any flux either liquid or paste on the mother board. Over time, the acidic properties of liquid or paste flux will begin eating away at the fiberglass PCB and will damage it. Use only Rosin-core solder or no-clean flux approved for electronics use.
TCS recommends the use of Kester "44" Sn63 Pb37, .015" diameter Rosin-core solder. Kester part number 24-6337-0007.
You can order this solder from the following retailers:
Digikey - PN:KE1110-ND
Techni-Tool - PN:488SO6775
Other solder tips
When stripping wire, only strip a tiny little bit of the insulation. Strip no more then a 1/64 of an inch. When the wire gets tinned with solder, the insulation will shrink back more. Try to not expose any more wire then half the length of the solder pad at most. In no case should solder or exposed wire wire ever be outside the boundary of the the solder pad you are attaching a wire to.
Click here for important information on properly Stripping and Tinning wire