Jumpstart Error

Start with a pile of blown fuses. Computers have diodes, which are one-way valves for electrical current flow), in them installed backward so it is like they are not even there. When the polarity is reversed, the diodes turn on and act like a dead short which forces fuses to blow to protect the rest of the circuitry.

The generators have diodes in them too for a different purpose, but they too will look like a dead short when the battery voltage is reversed. Look for a really big bolted-in fuse for those, or a fuse link wire. To test a fuse link, pull on it. If it acts like a wire, it is good. If it acts like a rubber band, it is burned open.