The LEGO 9V train motors are part of a discontinued system that ran from the early 1990s to the mid-2000s and are no longer available new from official retailers. They powered trains by drawing electricity directly from a metal strip on the 9V tracks.
The Original 9V System
The 9V system was popular for its reliability and "set-it-and-forget-it" power source, which was ideal for large, long-running train layouts at exhibitions.
Power Source: Power was supplied via a wired speed regulator connected to a wall outlet or battery box, which transferred the 9V current through metal contacts on the track.
Motor Design: The motors had metal wheels that made contact with the track's metal strips to draw power.
Status: The entire 9V system (motors, metal tracks, speed regulators, and power supplies) was retired and replaced by newer, battery-operated systems.
Availability of 9V Motors Today
Since the system is discontinued, you cannot buy new 9V motors from The LEGO Group.
Secondary Market: Used and sometimes new-old-stock 9V motors are available on marketplaces like eBay and BrickLink. Prices for these used motors can vary significantly, often costing around $70-$80 USD, depending on condition.
Reliability: The motors are generally very durable, but some issues may arise with the wiring's insulation over time, which can sometimes be repaired.
Modern Alternatives and Compatibility
LEGO has moved to a battery-powered system, with no official plans to return to 9V.
Power Functions (PF) and Powered Up (PU): These are the modern, battery-operated systems used in current LEGO trains. They use plastic wheels and an IR or Bluetooth connection for control.
Compatibility: Modern trains using the PF or PU systems can run on the older 9V metal tracks because the power source (battery box) is on board the train itself.
Third-Party Solutions: The dedicated fan community has created third-party solutions, such as new 9V compatible metal tracks (from vendors like Fx Bricks) and prototype motors or pickup wheelsets that work with modern PF/PU motors. These solutions allow enthusiasts to use the track-powered system without relying solely on vintage components.