ABS Trac off Airbag light on after battery change

purchased 2000 venture van. It was advertised with bad battery. I jumped it, test drove and decided to buy it. I drove it home with the old battery in place. There were no issues. No panel warning lights, no problems with trans. Car ran great. After getting home, I installed a new battery reinstalled fuseblock. When I switched the key on, I had a ABS warning light, Trac Off and Airbag light. These stay on constantly now although the brakes seem fine and the trans will shift hard sometimes, sometimes not. Everything was fine before the battery change. Could I be missing a connection. The battery connector to the fuse block spartks when I remove it and reinstall it. It didn't do that initially either.