gremlin

Buddy of mine got an indy dan rebuild last year on a 2010 800. Ran good. First time out sat he fired it up and it ran five minutes, the dash and rest of the lighting coil died but the machine kept running a short bit then died as well. Turn the key off and on and the whole same process starts over?????

Any ideas?
Im thinking bad lighting coil on stator. It grounds out and kills the accs. Keeps running till the ecu senses it and shuts down?