How to convert N Gauge Tomix EF63 to DCC

This guide covers the following models:

• Tomix EF63 in JNR first edition brown livery (EF636) (98005)
• Tomix EF63 in JNR third edition blue livery (EF6323) (98151)

These models are generally supplied in pairs, with one loco being motorized and the other being a dummy. Both locos have working lights.

Step 1 - Remove Body

Unclip the body by pushing upwards.

Step 2 - Disassemble Chassis

Unclip and remove the lighting PCB holders at each end. One has a PCB fitted, the other is empty as these models only have lights fitted at one end. It is fairly straightforward to retrofit lights into the empty end if required.

Unclip the two black retainers from the bottom of the chassis.

Unclip the front detail pieces from each end.

Step 3 - Modify Motor

Separate the two chassis halves. Remove the motor.

Solder and orange and grey wire to the inside of the motor contacts.

Put kapton tape on the outside to isolate the contacts from the chassis.

Step 4 - Reassemble Chassis

Route the wires up through the gap between the two chassis halves.

Put the two halves back together, replacing the lower black clips. The clips are designed in such a way that they can only be replaced the correct way round.

Reattach the front detailing at each end.

Step 5 - Modify Lighting PCB

The lighting PCB uses an LED for the red light, but a filament bulb for white.

Remove the lighting PCB from the holder.

Remove the switch and switch contact.

Desolder the diodes and resistor.

With the sleeving removed, desolder the negative leg of the red LED from the PCB. Solder a yellow wire to the leg, and add new shrink sleeving. Solder a blue wire to the other (positive) leg of the red LED.

Solder a white wire to a leg of the white bulb, and a blue wire to the other leg.

Solder a black and red wire to the outer PCB tracks, between the hole in the middle and the red LED legs. Make sure there is clearance for the chassis to still touch the tracks, you may need to route the wires more centrally. You can usually see where the chassis touches the PCB as it leaves a small indent/mark.

Refit the lighting PCB in the holder, and route the wires though the hole in the holder and towards the recess at the other end of the chassis.

Step 7 - Fit Decoder

Solder a 1k resistor to the blue wire.

Route the wires back into the dummy PCB holder through the same hole as at the other end.

Solder the wires to your decoder, then wrap the decoder in kapton tape.

Refit the dummy PCB holder.

Step 8 - Refit Body

Refit the body, and the conversion is complete.

To convert the non-motorized dummy loco, the process is the same except there is no motor to modify which means there is no need to separate the chassis halves. You can either reverse the white/yellow wires, or just wire them up the same and use CV programming on your decoder to make them work according to your prototypical requirements.