The use of working loco lamps in a model steam loco can be great fun, and add another aspect to your enjoyment!
Lamps are not prototypical on all locos, particularly if you are modelling early era scenes, where discs were more common for example,
but if you just want another feature to play with, then look no further!
Working lamps are perhaps the hardest of all equipment to install, since they can require careful drilling, routing and connection to
your decoder. Extra care must be taken to avoid shorting, especially in locos that have metal frames.
Ideally, each lamp should have its own resistor too, between the LED's positive leg and the decoder's BLUE 'common positive' wire. Failure
to include a resistor will instantly blow the LED, often with an alarming 'POP'! Sharing of resistors is possible, but you should only consider this where space is
at a premium, and where all LEDs from that resistor are controlled by the same decoder function output. For example, if you have 2 yellow
lamps on the buffer beam of your loco, which are switched on when the loco is travelling forwards, then these 2 lamps can share a resistor.
Use a resistor between 680ohm and 10k to get the desired brightness (YouChoos normally uses 1k resistors).
A variety of lamps are available, including YouChoos' own loco lamps, which are either 1.8mm or 1.5mm LEDs with shaped legs, painted, and
with fine decoder wire soldered. The lens of the LED is filed flat to match the look of a real railway lamp. Some have hooks on the top, some have
a loop, others have effect-lamp irons, and others have no extra detail at all (good for kids' models!). Alternatively go for lamps from
Express Models, First Class Trains, or use the excellent DCC Concepts working lamps.
Whichever lamps you decide upon, you've got to drill some small holes to mount the lamp, but don't be afraid of this - the hole is usually
hidden by the lamp anyway. Fix the lamp in place with a dab of super-glue - careful not to use too much, or you'll get it on the loco's body.
The wires must then be routed somehow to the decoder inside. This is perhaps the trickiest part, and requires careful planning to
ensure that nothing will get sheared or stretched to braking anywhere en-route. You may need to file some channels in the loco chassis or body
for the wires to sit in, so that the body of the loco can sit properly in place afterwards. A Dremel-type tool, or hand files
can be used for this.
Fix the wires to their chosen route, using glue if you want it to be permanent, or something tacky like silicone RTV if you want to be able
to remove it later.
The positive wire of each lamp then needs to be connected via a resistor to the decoder's BLUE wire, and the negative lamp wire should
be connected to whichever function output wire of the decoder you choose. For directional lamps, choose WHITE or YELLOW, for Forward or Reverse
Below are shown DCC Concepts' working loco lamps, which are more expensive, but painted and weathered, look fabulous. Wires from these lamps
are ultra-thin enamel-coated, so you can route them almost anywhere...