I have an 87 Warwick NT Thumb that I recently acquired. It came with LED SideMarkers, which do not work. I looked at the Obvious, and Thought I had found something, as the RED wire connecting to the battery was seperated. I soldered it together, and no joy. So, I'm assuming that the Lights are engaged somehow by the Input Jack being inserted into the Instrument. But so far I haven't completely torn this baby down to Parade Rest to trace the wiring. Does anyone have any experience with LED SideMarkers? I would apreciate any suggestions.