Eletrical Problem

Use a digital multimeter across the battery posts, everything off, around 12.6 volts is the generic spec for a full charge. You can't test anything unless the battery has a full charge. If engine will run, take second reading across battery posts, engine running, the second reading should be higher than the first if charging system is working?

With everything off, if excessive battery drain, you pull and replace fuses one at a time, when you kill the faulty circuit, the drain goes away. You should use an amp meter to check for draw, I believe.030 is about normal. Also, you can take a battery cable loose, use a testlite between cable and post, if the lite stays on bright, you have a drain, then you start with the fuses. Pay attention to interior lamps and lamp underhood should be off.

I haven't looked at you headlamps yet?