86 FJ 1200 2 electrical gremlins

[SVT4CAM]

Didn't ride the old girl much last year but I was having problems with the bike almost dying when I hit the front brake lever, dash lights dim, and the brake light actually dims when front lever is applied some sort of short or bad switch and how to find?   Other problem is the girl kills batteries like Hannibal Lector kills people.   I'm sure it's overcharging but how do I test/fix it?  I'm great with wrenching but electrical stuff leave me scratching my head.  I do have a multi meter just not sure how to use it for testing these components.  Thanks

[Arnie]

Start the bike, connect the mult-tester to the battery terminals.  Pos to Pos, Neg to Neg.
You'll need to rev the bike to 3000 rpm and the voltage should not be more than 14.5 Volts.

Once you report back that number, we can go onto part 2 - fixing it.

Arnie

[rktmanfj]

I'd consider fixing the short in the front brake light circuit a priority over the overcharging issue.