I put it into gear and it dies.

yeah. I thought I did it wrong when It kept running without the key.
new lesson. double check before trying stuff.
Plus, you've "really" not isolated the ballast. You bypassed the whole circuit, so if there's a broke connection "other" than the ballast, you missed it. If you bypass "just" the ballast and it runs, you've narrowed it down "bout" as far as you can. lol