You have a live exposed wire hitting somewhere off the frame or engine creating a short circuit in the wiring loom. Basically when you turn the bars the loom is getting pulled in towards the frame & rubbing off it. This constant rubbing has probably worn through the protective outer covering & wires inside making them earth off the bike.
Look along the wiring loom for any chaffing or rips, if you find the exposed wire & it's not broken, then tape it up with some electrical insulating tape. Try & move the loom so it's not going to be rubbing off that particular spot again.
Hope this helps...
Steo
November 2009
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