How to convert Graham Farish Class 91 91004 (8807) to DCC Sound

This guide covers the following models:

• Class 91 91004 Intercity (8807)
• Class 91 91005 Intercity (8807)
• Class 91 91007 Intercity (8807)

The Graham Farish Class 91 GNER model was made in China and has a different chassis arrangement. Please contact us if you are interested in having this model converted to DCC sound.

Step 1 - Fit Digihats

First, follow our Graham Farish Class 91 digihat conversion to install two digihats, one at the top and one at the bottom of the chassis. You will end up with the motor brushes isolated from the chassis, and a grey and orange wire ready to connect to the decoder socket.

Step 2 - Prepare Chassis

Drill two small holes into the plastic at each side, as close to the metal as possible. These will allow us to pass wires up into the body from the decoder socket installed under the floor.

Step 3 - Install Next18 Socket

Turn the loco over and glue a Next18 socket just next to where the digihat was installed. Solder black, red, white, yellow, blue and two brown wires to the socket PCB. Pass all but the black and red wires up through the holes drilled in the previous step. Also pass the wire from the lower motor brush up into the body.

Step 4 - Connect Track Pickups

Tin the end of the black wire and trap it under one of the large screws. This will provide one of the track pickups to the decoder.

Solder the red wire to the copper strip to provide the other track pickup.

Step 5 - Connect Motor

Solder the orange and grey wires from the motor to the decoder socket.

Step 6 - Fit Speaker

Using a Dremmel or similar tool, cut the end off one of the chassis end pieces as shown.

Refit the bogies and reassemble the chassis.

Glue the speaker to chassis and solder the two brown wires to it.

Step 7 - Fit Lighting Socket

We will be retrofitting directional LEDs into the body at a later date. This optional step installs a socket to make it easier to separate the body from the chassis, as the lighting wires can simply be unclipped. With suitable decoder programming, you can alternatively use this wiring for cab lights.

Solder the blue (common), white and yellow wires to a mini socket, and glue it to the side of the chassis.

Step 8 - Refit Body

Refit the body and the DCC sound conversion of your N Gauge Class 91 model is complete.