Well Sean.
I'm no expert. But I'd have to say that you better break out that "Digital Multimeter." And spend some quality time alone with that device. And nermous wires and componants that you'll have to trace down. And find that spot, where you are losing your power.
Working on automobiles is very similar. And believe me. It's a pain in the ass to work with. I even admit hating to deal with it!! That's the only way of truily finding your little culprit in the act?