HO Scale

DCC Quick Light Board

The aux lights (beacon, mars, gyra, ditch, etc) are installed connected to the headlight tabs (along with the headlight bulbs), if you want to have the aux light effect with independent control via a decoder then you have to move the aux bulb wires to other tabs.
In the pic, the tab circled in white is the 1.5V output controlled by the white wire of the 9 pin JST connector.
The tab circled in blue in connected to the blue wire of the JST connector and is the plus voltage common.
The hole circle in green is connected to the green wire, this is a track voltage output, not regulated.
The hole circle in violet is connected to the violet wire, this is a track voltage output, not regulated.
What I usually do if I have a loco with a aux light is leave the head light bulbs connected the headlight tabs and remove the rear light bulbs and wire the aux light to the rear tabs then use a 12-16V bulb connected the green hole for new rear light, changing the function mapping.

C44-9W

Lenz LE103XF, light bulb for headlight, no rear light.

F45 blue box

Soundtraxx DSD installed in a dummy with two 1.6 x 1.1 speakers, and a white LED for headlight, no rear light.

Lenz LE-103XF installed, remotored with A-Line motor.

Gas Turbine

QSI Revolution-U.  The 1.5V bulbs Athearn uses are OK when they are used in hole in the light casting and you view them directly, but the turbine has lenses so the light was too dim, I changed the bulbs to warm white LEDs.  I also added LEDs for the number boards.  For more info on decoder install see:
http://www.tonystrains.com/technews/qsi-revo-turbine.htm
http://qsisolutions.com/news/09/adding-sound-turbine-072809.html

PLCC SMT LED for headlight connected to head light tabs of factory PCB, no additional resister needed.
3mm LED for Mars connected to F1 tabs of factory PCB, no additional resister needed.
2 PLCC SMT LED for number boards connected to white/green stripe and red/white stripe wires with 220 ohm resistor for each LED.

Did not catch the mars while it was full brightness.

Quicktime video (4 meg) of mars light, note sound not very good in video because the digital camera I used only does 4 bit audio with crappy internal mic, loco sounds much better than the video.

GP60

Be careful of Athearn RTR locos, here is a GP60B showing that the bottom motor wire was pinched between the motor and frame.  Vibration could eventually ware though the insulation and smoke the decoder.

Soundtraxx Tsunami with High Bass speaker in cab.

SD40-2

A Kato motor/flywheel/mount/PCB, reusing the Athearn hex dogbone drive shafts (they fit the Kato flywheels just fine).  Unfortunately, the PnP decoders the the Kato motor mount table are too wide to fit into the Athearn shell, but the Kato PCB and a NMRA 8 pin plug decoder does fit fine.  Note the Kato motor assembly has to go into the Athearn chassis backwards (the front of the Kato motor points to he rear of the Athearn chassis).

SD40T-2

Soundtraxx Tsunami TSU-AT1000 with bass reflex speaker, speaker is a tight press fit above rear grills.

SD45T-2

Soundtraxx Tsunami with bass reflex speaker.

EMD Model 40

A Lenz LE0511, I removed the factory plug and installed the decoder under the holder for the factory plug.  The cab is left mostly open.  I also changed the white LEDs to sunny white LEDs.