Installing custom lighting in Kato Nippon Sharyo Bi-Level Cab Cars using LokPilot Nano Fx decoder

Kato has come out with a number of commuter car sets (CalTrain, Metra, VTA, etc) which have the Nippon Sharyo bi-level coaches and cab cars. The cab cars even come with an innovative lighting board which allow for the red class lights to be on while travelling forward (cab at end-of-train), or headlamps and ditch lights on when the cab car is leading. The Kato FL-12 function decoder works well for converting these cars to DCC, but the board and light pipes do not allow for flashing ditch lights (all lights fed from same LED). After installing an ESU LokSound into my F40PH CalTrain loco, I wanted to upgrade my cab cars to allow for more realistic performance of the lights.

I chose to use the new ESU LokPilot NanoFx decoder. This is a 6 function decoder only 8mm x 7mm x 2.8mm in size; compared with the LokPilot V4 FX (17.5mm x 15.5mm x 5.5mm). Although going into a passenger car, I wanted to use the smaller decoder. (Ok, it was more expensive and not quite as flexible as its big brother, since it is based on the LokPilot V1 functional architecture instead of the new V4). But, as will be seen, it does the job well.

As I had never seen anyone document converting these cars, I decided to take a lot of pictures and provide a more complete description on how to add a decoder and independent lighting to these.

STEP 1: Open up the lower access hatch on the bottom of the car. This is either where the slide on/off switch (for DC) or Kato FL12 DCC decoder sits. Remove the switch/decoder, and leave the hatch cover off until much later in the conversion.

STEP 2: Remove the body shell. Start at the front end of the cab car, and carefully spread the shell and pry out the end of the floor. Everything on these cars fit extremely tight, so have a couple of toothpicks handy. Once you get the front end of the car started, the rest releases easily, but don’t just pull. You need to angle the shell off, so as not to damage the light pipes which engage in the cab end.

Set the shell aside

STEP 3: Remove the Cab Detail / Upper Light Tower housing (grey piece). This detaches from the lower interior detail with two snap clips, one on either side. Set this piece aside




STEP 4: Carefully lift off the lower interior detail and floor. A series of press tabs along both sides hold this in place to the bottom frame. Start at the cab end, and work your way forward releasing each tab. Note: The second tab forward, on each side, from the cab end is DIFFERENT and molded on the side frame



Set the interior detail aside.

STEP 5: Remove brass triangular springs from between the light board and brass power strips. These will not be reinstalled.


STEP 6: Unclip the light housing tower; snap clips from frame on either side




STEP 7: Remove orange-ish light pipe. We will not be reusing

 

STEP 8: Carefully pull out the circuit board. We will be connecting wires to this board to provide the lighting to the red class / EoT lights.

STEP 9: Attach 3 warm white (incandescent) SMD LEDs to the light tower as shown. I use 0402 LEDs for the ditch lights and an 0603 LED for the headlamp. Besides removing the orange light pipe (step 7), no other changes are required to the light pipe in the tower. For a quick attach of the LEDs, I use Bondic – a UV cured adhesive. Use the tip of a small file to roughen the surface of the plastic prior to bonding




We could use a 4th SMD on the red light pipe as well, but the circuit board also provides light blockage / protection, and hey, we have it!




STEP 10: See the diagram for the circuit board. What we want to do is use the “top” LED on the board, which feeds the red light pipe. Pad D in the diagram is the cathode (blue decoder wire) for this LED; Pad B is the Anode (yellow decoder wire). (Note: by using these pads, we utilize the resistor on the board.) To ease the installation, I use magnet wire to connect to the the board, for space and flexibility.


Step 11: Bring the wires from the light tower up through the hole in the circuit board. Seat the board back into place, and put the light tower back on the frame and snap into place. Make sure no wires are pinched, and the tower is sitting flush.

 

STEP 12: Now it is time to put in some new holes! We need to put 3 holes into the floor of the lower detail piece, to pass the 4 sets of LED wires, as well as power pickup wire, into the cabin for attaching to the decoder.

We will put these holes at the open space in the frame where the access hatch, removed in Step 1, goes. The positions are marked in the photo.




I use a 3/64” drill bit to make slots on the two sides (gives you some leeway with the power pickup wire) and a 1/16” bit for the central hole. Use a hobby knife and small file to clean these up (photo before cleaning)




STEP 13: Pull the LED wires through the opening in the base, to get them out of the way. Solder a red and black wire to the pickup strips. For these, I’ve used TCS 30 SWG flexible wire.




STEP 14: One last thing before feeding the wires through the interior floor – we need to add more weight into the well that is beneath the supplied Kato weight. (insert 5208) I use lead tape, which can be purchased from golf / sporting goods stores. Cram as much in as you can, keeping it so the Kato weight still sits flush to the frame.

STEP 15: Feed the black and red wires up through the side slots you cut, and carefully snap the floor back into place. DO NOT FORCE! If any resistance check for obstructions (wire, brass strip not seating properly, etc.) and fix. Once the floor is properly seated, replace the grey cab detail (top of light tower) that was removed in Step 3.

Feed the LED wires up through the central hole in floor

 

STEP 16: Before going any further, it is a good idea to test all the LEDs one last time. This will also help isolate the leads for each lamp, so we know which decoder wire goes where. For LED testing, I live by the Ngineering Intelligent LED Tester (http://www.ngineering.com/other_cool_tools.htm). It attaches to a 9V battery, and has a current regulator on the board which prevent blowing out your LED by forgetting a resistor.

If all is well, you can now replace the access hatch cover in the bottom of the frame.

STEP 17: Next I solder the LED wires to a small circuit board with SMD Resistors pre-soldered to it. I use 1/8 watt 1000 ohm resistors. The board is made from 1/32” single side copper board. The slots are milled in to separate the different contacts. The board is ~0.475” square, and fits perfectly inside the central area of the lower level (behind the doors).




In the photo, there are only 3 resistors. That is because we are using one of the resistors on the circuit board, for the red class lights/EoT markers.

I attach my wires as follows (from right to left in the photo)

• First full strip – All the anode wires (connect to the blue (Common +) from decoder)
• Second full strip – Cathode to board LED for red lights (yellow wire from decoder)
• First resistor strip – Cathode to headlamps (white wire from decoder)
• 2nd/3rd resistor strips – Cathodes to ditchlights (green and purple wires)

STEP 18: At this point, it is time to wire in the decoder. The functions are listed above, and the red and black leads of the decoder need to attach to the wires coming through the floor from the power strips. I have also attached 3 25V 150uF Tantalum capacitors to the decoder, to act as keep alive. Passenger cars are very light, and this helps eliminate flicker and decoder resets. Check to see if your decoder supports this, if using a different one.

Once wired, I put the little wiring board into the space behind the doors, and hold in place with double sided tape.




At this point, we can put the shell back on. I slide the capacitor pack up into the front end of the car, on upper level, and the decoder into the back end’s upper level. Carefully angle the shell back on, cab end first, to engage the light pipes. Make sure no wires are being pinched.

 

The video demonstrates the two installs I have completed. I have set the lights in one cab car to operate on F6, and the other on F7. I have, on the loco, set the LokSound function labels for those buttons (as well as in Decoder Pro) to read “Cab Car 4022 in use” or “Cab Car 4024 in use”. There is also alternative logic used on the loco’s rear headlamp, such that it only goes on if neither F6 nor F7 are active. For the video, I have both selected.