My brother's 87 240 (bomb) keeps blowing fuses.

Since he would sooner jump off a bridge than take any advice from me, I've been trying to gather what I can from my dad and then suggesting stuff to my dad to get back to the brother. For this reason, I can't get to the car often and check it myself--that's why I'm soliciting suggestions.

Bro went to Europe for the summer so I got to work on his car (no thanks whatsoever). I put in new battery cables and cleaned the fusebox.

Apparently he got a new battery recently, much larger than the old one. That seems to be the time when the fuses started blowing. He's blowing several different fuses, and they don't sound related in any way. From what I can gather, he's using new fuses (not old ones lying around) and it keeps happening.

I'm thinking either the battery is just too much for the car, or maybe the old battery got fried because the alternator is overcharging, and this just magnified the problem or brought it back.