A dummy plug is what keeps a converted N scale locomotive running on DC while you wait to fit a decoder. Plug a DNDP into the harness in place of the decoder and the motor circuit is completed for plain DC operation; pull it out, drop the decoder in, and the same locomotive is DCC. This is a five-pack, which is the sensible way to buy them - they are small, easy to lose, and you always need one at the wrong moment.
Building a DCC fleet? Browse our DCC Decoders, DCC Wiring, and DCC Accessories.
What does a dummy plug actually do?
It bridges the motor and pickup connections so the locomotive runs on plain DC. Without it, or without a decoder in its place, the circuit is open and the loco will not move.
Do I need one if I am fitting a decoder?
No. The decoder takes the dummy plug's place in the harness. Keep the plug somewhere safe though - you will want it if you ever pull the decoder out for another project or sell the loco as DC.
Will these work in HO?
These are the N scale version, for the DNWH and DNWHPS harnesses. HO installs use the corresponding HO parts.
Why five?
Because they are small, unlabelled and easy to lose, and because most people converting a fleet are doing several locomotives at once.
