Ice Cap ballast Wiring Question

[Andy]

I was splicing the black, white and green wires coming from my Ice Cap 660 wiring harness to a grounded power cord and was wondering whether it matters if the black and white wires are switched. My grounded power cord has a green wire and 2 coloured white so I don't know which is hot and which is neutral. I've already wired it together one way and the lights come on for a split second then shut down. Something is amiss. Any ideas.

Thanks,

Andy