Fitting a decoder to R320 1995 West Country Exeter 4-6-2

[37lover]

I have the loco in the title which runs well on DC but I would like to convert to DCC. The closest service sheet is #177.

I am no stranger to fitting decoders & soldering but no expert either.

The following two photos show a top view of the motor and also a side view

The top view shows the upper terminal for the motor, labelled B2 which is connected to a cable off to the left which pick up power from bronze wipers behind wheels on one side of the loco, and the other cable secured to the block at A2.

The side view shows B1 [same terminal as B2], A1 [same as A2] and the other motor terminal C1. C1 is connected directly to A1/2. There is also a "blue" suppressor/capacitor connected between B1 and C1.

I assume that I can take the feed from the wipers [i.e. disconnect from B1/2] and connect as a feed to a decoder and take from A1/2 as the other feed to the decoder. I would remove the suppressor and "obviously" the existing connection from A1/2 to C1. The outputs from the decoder would then go to the motor terminals B1/2 and C1. Is this correct or will there be a short somewhere from the "live" chassis.

Thanks for any confirmation or correction.

[jane1707819582]

Decoder red to the wire B1

Decoder black to the wire at c1

Remove suppressor

Orange to connection b1

Grey to connection c1

Ensure motor isolated from chassis connections b1 and c1

[37lover]

Jane2,

Thank you for your reply.

I think you are confirming what I had proposed but to be absolutely clear when you state Decoder black to the wire at C1 that means disconnect the wire from C1 but leave it connected to A1, which is the same as connecting decoder black to A1.

Not sure what you mean by the last sentence, unless of course you mean remove the black wire between A1 and C1. As far as I can tell there is no existing chassis connection to B1.

[jane1707819582]

Either or at connection a1/c, connecting at c1 gives you a little more wire to slot the decoder in a good position .

My last sentence is a,belt and braces test just to ensure the motor is electrically isolated from the chassis in my view better checked than a blown decoder .