It is possible.
you would have to check for power at the relay from the key on side/blue wire to the bulkhead when it dies.

staying running once you let off changes the circuit to ign 1.
you could be moving something enough to get intermittent drops and reconnects.

Next time it dies, leave the key alone.
Check for power at the relay/bulkhead.
and to the ballast. if it is missing, then I would go for the ign switch and check for power in and out there.