Summary: DCC-ready locomotives with 8-pin sockets are shipped with a factory-installed 8 pin blanking plug that shorts the rail pickups to the motor terminals (and headlights) in the absence of a decoder. This plug must be removed before installing the decoder and must be replaced if removing the decoder and returning it to analog operation. The 8 pin version is known as the medium size and was the most common standard DCC connector used in HO and O LOCOMOTIVES