Got my first locomotive that needed a 21-pin decoder. (Walthers GP-7) Selected, purchased and installed this ESU 59029. Installation, programming CVs and operation was as expected BUT, no headlights! I don't know if it is the decoder or locomotive or lights. They worked fine in DC! Until I discover the issue, the locomotive will be in trailing unit service position. Never had this issue with any other locomotive or DCC decoder or combinations.