1) Here's the wiring diagram: http://www.icecapinc.com/downloads/660wiringdiagram.pdf

2) Do a continuity check from your harness where it plugs into the ballast: http://www.icecapinc.com/downloads/cont_test.pdf

I'm going thru the same thing with my VHOs. Just haven't had the time to completely troubleshoot.

BTW, you can't test voltage - the Icecap will shut down immediately if it fails to light. Also, you must recycle the ballast when making changes - because it shuts down immediately.

And yes, their support is outstanding.