I dont think its a wiring problem but its possible. If it was me, Id go ahead and buy a replacement, plug it in and try it. If it works, great. If it still has the same problem, then you have a spare light for when one does go out, and youll have to get back to looking at the wiring. http://www.basscatstore.com/marinetaillight.aspxJim EbarbMany, LA (Toledo Bend Lake)2004 Cougar/ 225 OptimaxHumminbird Helix 12 Chirp SI on BalzOut Mount at bowLowrance HDS 7 at bowHumminbird Helix 12 Mega SI on Ram Mount at ConsoleLowrance HDS 8 in dash at console