Fans doesn’t shut off

[Zman]

Took my 1991 out last weekend on a bumpy road. When I got back and parked the car my fan kept running after the car was shut off. Left it thinking it will cool and shut off. Today it had a dead battery. I jump started the car and drove it for about 15 minutes. The fan turned on immediately when the cables were hooked up and continued to run after the short drive. When I went to disconnect the battery I noticed the negative battery terminal was loose. I will try recharging the battery and tightening the battery cables. Anyone ever had an issue like this? The fan that runs seems to be the blower fan for heating and cooling.