93 Caravan TD27ti *Dash lights / Battery*

[Oldbog]

Just put in a new battery in, old one tested bad, redid all terminals as the where old. Van started up great, go to test drive it with a potential buyer and buzzer alarm starts going off, all dashboard warning lights come on, brake became very hard.

I’m thinking alternator (even though that doesn’t explain brakes) but other than fuses and serp belt what else should I check?