Most likely has the "floating ground" that Gm used, a real PITA.
Make sure that all the metal frame parts have a good ground strap connection.
Old Cat Rider
'93 Wildcat 700EFI w/ Comet 108 Pro-4 clutch & 01 ZR skid
we are all given sh*t in life, but some of us learn to turn it into fertilizer and grow from it, and some us try to fling it on others like monkeys