Hi all,
Follow up to the request for help.
I managed to wire up a TCS M1 decoder with the harness cut off and the loco runs (well). I even wired up some new LEDs for the headlights with a resistor on each. However ... whilst the light at one end works fine (only on in direction of travel) the other end doesn't work at all. The LED is definitely working. One curious thing (which to anybody with an understanding of electronics may help) is that placing two wires and a bulb across the + and - wires leading to the LED result in the LED turning on. Any ideas please?