Graham Farish Class 66 DCC Conversion

This guide covers the Graham Farish Class 66 diesel loco which has a DCC-friendly PCB. The conversion requires removal of two brass clips, and the soldering of seven wires onto the correct solder pads on the PCB. Examples include:

• Class 66 66610 Freightliner Green livery (371-376)
• Class 66 66623 Bardon Aggregates Blue livery (371-394)

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.

For the full guide, follow the 7 wire PCB method. For this model, a Doehler & Haass PD10MU-3 decoder was used which is small enough to tuck in under the lighting wires at the long cab end. This decoder also has a lighting common solder pad, onto which the blue wire (solder point #7) has been connected.

Step 1 - Remove body

Remove the body by gently prising the body away from the chassis and pulling upwards.

Step 2 - Remove copper clips

Locate the two copper clips in the bottom right hand corner of the PCB. They have numbers 8, 1, 2 and so on immediately above them. Remove the clips to reveal seven solder points.

Step 3 - Connect decoder

Connect the wires in order according to the table below. If your decoder does not have a lighting common (blue) wire, you can connect a small bridging wire between solder point #7 (blue) and #8 (red). The decoder will tuck in underneath the lighting wires. You can optionally use a small piece of black tack to secure it. Make sure the decoder is suitably isolated from any metal parts of the chassis using some tape.

Step 4 - Test

Place your loco onto your test track and read the loco ID. It should shuffle a few times and then come back with the default loco ID of 3. You can then try running the loco backwards and forwards, and check that the directional lighting is working correctly.

Step 5 - Refit Body

Refit the body and you are done!

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