Are you running DC or DCC? NCE has a decoder that works on DCC and some limitions on DC. Manual:https://ncedcc.zendesk.com/hc/en-us/articles/360002094233-Light-it-and-Illuminator-Manuals
decoder:https://www.ncedcc.com/online-store/Light-It-3-3-pack-of-the-Light-It-Universal-Lighting-and-Signal-Decoder-p78626959
keepalive caps.:https://www.ncedcc.com/online-store/search%3Fkeyword%3D5240306
I have installed these on several cabooses for rotory beacon affect( DCC system)
Joe
Last year I had seen a youtube post decribing how to light the tail sign on the Walthers City Of Portland tail observation car, since then it has been deleted.
Narration was given, but did not show a wiring diagram. I'm assuming that a balllast resistor, and keepalive capacitor are needed along with the LED lamps. I would welcome responce from anyone having done this.