This installation documentation is for the Kato EMD SD70 and SD70ACe. This installation uses the K1D4-NC decoder and was performed by A.G.
This installation requires special procedures so be sure to follow each step!
TCS also produced a companion video for this locomotive installation, which details disassembly, frame milling, and installation of a K1D4-NC decoder and Keep Alive® device. Scroll to the bottom of the page or click here to view the installation companion video.
Picture of Kato EMD SD70ACe with its shell on.
Gently remove the locomotive's shell by squeezing and pulling upwards starting from one end (as shown in the picture).
Picture of the SD70ACe's chassis with its original lighting board and copper clips.
NOTE: Due to the flexing required to remove or install ANY board in this locomotive the frame contacts are prone to loose connections. The image below highlights the original lighting board with a gap between the pad and the frame which opens the circuit and prevents the locomotive from receiving power.
This problem does not relate to the type of board being installed. In fact we installed the original Kato lighting board and the same issue occured. The picture above shows the gap between the locomotive chassis and the original Kato lighting board which we reinstalled.
Now, remove the motor clips from the lighting board and using a small flathead screw driver. GENTLY lift the section highlighted above on original lighting board up using the screwdriver so that the board may slide backwards across the chassis.
After the original lighting board is removed, place a piece of kapton tape over the chassis in order to insulate the motor clips from the frame. Make sure the kapton tape is laid flat on the metal chassis. It is also necessary to wrap the tape down the side of the frame to cover any potential contact points.
Next, place the clips form the original lighting board on the K1D4-NC decoder as shown in the picture. (You can also perform this step later on, after you place the decoder in the chassis' slots - see next couple of pictures). TCS recommends the use of solder to secure these clips once they are installed onto the decoder for improved performance.
Now slide the K1D4-NC decoder back into the frame the same way that you removed the lighting board. Start the decoder in at a slight angle (as shown in the picture) and then slide forward and gently press down on the rear of the decoder. It will click into place when correctly installed. DO NOT APPLY EXCESSIVE PRESSURE OR YOU WILL SNAP THE DECODER. Also ensure the decoder is mounted with the components facing upwards. The decoder will not fit if installed upside down and will damage components or break entirely.
This is a picture of the Kato packaging foam (found in the locomotive's box) that can be used to secure the loose connection that we mentioned earlier. NOTE: On some more recent models, Kato has corrected this issue by including their own foam wedge.
Cut a small piece of the foam from the upper region of the packaging. Next slip this piece under the decoder between the frame posts. Then use a flat head screw driver to push the foam in deeper and confirm a tight connection between the decoder and chassis. Check the image above to make sure you are performing this step correctly.
Here is the picture of properly installed K1D4-NC.
This picture shows the K1D4-NC installed with motor clips attached. Make sure that the motor clips are lined up with copper motor contacts.
This picture shows how isolation should be done.
NOTE: Depending on the vintage of your model, this step may not be necessary! In order for the shell to be properly fitted on the locomotive chassis, four (circled in red) plastic pins need to be trimmed off. We suggest using an X-acto knife, but be careful not to cut throught the shell. This can be tricky, so be careful.
Place the locomotive's shell on its chassis starting from one end and working your way across.
Here is the picture of the beautiful Kato EMD SD70ACe with K1D4-NC installed and ready to run! If you are interested in adding KeepAlive to your Kato N-scale SD70 models, check out our companion video below!
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