Motorcycle Repair: electrical, crane hi, electronic module

Question
1983 FXSB lowrider, i am stationed in Japan and bouught this bike from a friend, he had let it set up for a year outside. two questions. the tac and instruments lights only work when i apply the rear and front brake. is this a short to ground? when i first start the bike it will run ok but not idle after the bike warms up it sputters and backfires through the exhaust. i am thinking it is an electrical problem. i recently purchased a crane hi 4 dual electronic module and coil. is it going to help? current mods on the bike. s&s super E carb, s&s stroker 93 CI.sidewinder kit with 514 cam.  

Answer
The problem with the wiring is probably s short, so your going to have to trace out the wire to find it.
As to not running right, since the bike has been sitting for quit a while I would suspect that the carb is gumed up and needs taken apart and cleaned.
Good luck and happy riding
Mike