As for the hummer and diesel questions.. Those engines do not require an electrical system to continue funtioning. As long as fuel is still pumped (engine driven fuel pump?) it will still run. The guy in the snorkel video could have totally sizzled every electrical component in his rig and driven away happily (with no lights, stereo, etc, etc). The engine might run bad with no ECM helping it manage but the essentials for combustion would still be there. Just my $.02

JD

88 Pickup,4x4, 2.6 L, AMC head, K&N Air filter, Aisin Hubs, Redline Oils everywhere, 94 Trooper wheels.