Blowing battery fuse

I suspect there is more to the story that you may or may not be aware of. That fuse protects the generator in case it becomes shorted, which is not common. More often these large fuses blow when someone bumps a wrench to the large output connection on the back of the generator and to a metal bracket or part of the engine at the same time.

My concern is the wiring diagram does not show anything else tied to that circuit that is not related to the charging system. Some manufacturers will use the generator's output terminal as a convenient tie point for other circuits rather than running multiple wires back to the fuse box. One of those lines could also have the intermittent short. We can pursue that if it becomes necessary.

It is likely other fuses are blown causing the other circuits to be dead now, but it is difficult to figure out what all these blown fuses have in common. That is the "rest of the story" we do not know. Is there any chance the battery is not bolted down securely and the positive terminal contacted a metal bracket when it shifted momentarily? Also, check if either battery cable clamp is loose.

Here is an article that might help with locating other blown fuses:

https://www.2carpros.com/articles/how-a-car-fuse-works

From all the other fuses that I had checked none of them have blown. This might help also when I was reconnecting the battery back when I replace the battery fuse I did have a spark from when I was reconnecting the ground terminal, but the spark also came from an area closer down by my headlights. Which I think might have been connected to the positive terminal.

Be aware there is a fuse box under the hood and another one inside the vehicle. Also, when reconnecting the battery and sometimes when connecting jumper cables, there can be normal current surges that cause some fuses to blow. In those cases there is really no defect. You just have to replace them.

The way I like to approach this is to pick just one circuit and start with that. The brake light circuit is pretty simple and straight forward. The diagram shows a 20-amp fuse for this circuit. It looks like it's labeled "22" but you might find it listed on the fuse box cover as "brake lights". There are two tiny holes on top for test points. Check for twelve volts on both of them with a test light or a digital voltmeter. If you only have it on one of them, that fuse is blown. If it is missing on both, we will have to work back toward the battery.

If you have twelve volts on both test points, that fuse is okay; then check on the "red/black" wire on the brake light switch. That is a red wire with either a blue or a black stripe. You should have twelve volts there all the time. If you do, check on the brown/red wire. That one should have twelve volts only when you press the brake pedal. Let me know what you find.