Massimo Buck 250 won't start - engine light on

[BeachBuggy]

Massimo Buck 250 less than a year old.  900 miles on it.  Live on beach in TX...i.e. corrosive salt air and normally mild temps.

The story - one day, it randomly quit on idle and was tough to restart.  Next day, it occasionally cut out for 1-2 seconds while driving, then catch back to normal throttle.  Pumped gas pedal, not sure if that helped it catch.  Added some marine sta-bil and filled tank.  Ran well after that for a day.  Following day, wouldn't start.  Turns over, cranks, but won't start.  When it quit on idle that was the first time driven since we did have a freeze of ~25 degrees.

Full charge on battery. No spark.  Changed plug and still no spark.  Fuses look good, but fuse connection box has some loose clasps and spade were corroded. I bent clasps best I could and used dielectric on spades re-inserted.  Cleaned and checked every connection I could find.  Don't have a card reader to hook up, but did swapped ECU just to check that, and no change...after swapping ECU the engine light now stays on.  Previously blinked and then goes away.

Under warranty but service place is 2 hrs away. 

thanks!