Bachmann OO Gauge Class 03 & Class 04 DCC Conversion

Mistakes may damage your locomotive, controller or other accessories. Use a multimeter to make absolutely sure you have completely isolated the motor from the track before testing. Always use the Programming Track for testing. Our guides are provided for reference only, and you proceed entirely at your own risk. Unsure about something - try our DCC Conversion Service instead.

This guide covers Bachmann OO gauge split chassis models, such as the Class 04 and Class 04 shunters. It also applies to other locos with a similar arrangement:

• Bachmann Class 03 03197 in BR Blue livery (31-353)
• Bachmann Class 04 11217 in BR Black livery (31-339)

Step 1 - Disassemble Chassis

The motor sits inside two chassis halves, and gets power from the track via sprung contacts that touch at each side. To convert to DCC, it is necessary to stop the motor contacts touching the chassis.

The first step is to disassemble the loco and split the two halves.

Step 2 - Isolate Motor

Remove the motor. Put some kapton tape along the chassis surfaces where the motor contacts were previously touching it. While the motor is out, cut off the copper spring contacts as far back as you can. Solder a grey and orange wire to each side of the motor.

Put the motor back in, and route the grey and orange wires out. When the chassis is put back together, they will emerge from the gap between the two halves.

Step 3 - Connect Track Power

Strip about 8mm of insulation off the red and black wires. Scrape off any black paint from the inside of the circular holes where the chassis screws go. When the chassis is reassembled, the black and red wires will be trapped between the screw head and the chassis on one side, and the black retainer and the the chassis on the other.

Step 4 - Reassemble Chassis

Put the two chassis halves back together and tighten the three screws, trapping the red and black wires against the chassis at either side as previously described.

Step 5 - Connect Decoder

Solder the four wires onto the decoder as below. There is room inside the body for a 6-pin socket, so you can optionally install one of those for convenience if you wish.

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