The T1 LED has added Blue and Black/White wires for the use of a KeepAlive device. This decoder has internal resistors for LEDs eliminating the use of external resistors for F0F or F0R. This decoder may be hard-wired or plugged directly into any locomotive with a 9-pin JST plug. Use the standard T1 decoder if your locomotive uses incandescent bulbs.
Note: The Green and Purple wires on this decoder are not used. The T1-LED is a 2-function decoder, but still uses the 9-pin JST which includes the Green and Purple wires.