Engine Fan

Today i went to the mall, and when i came back my engine fan was on, no biggie that happens. But now about 5 hours later it’s still on. Anyone have any ideas what’s going on?

EDIT
Ok, i went back and checked again and it’s the passenger side fan which as i understand is the AC fan i just disconnected it because it’s killing my battery. What should i do next?

check the relays sometimes they get water in them and rust up and act as if they were energized. their both on the drivers side of the engine comp. next to the little fan. i think the little fan is the a/c fan . it also comes on if the oil temp. gets above 220 degrees F.

Well yesterday i plugged the fan back in and drove around for a while, and it hasn’t turned back on so i think i’m ok for now. I think there probably was some water because it had been raining very hard the day the fan came on. I also checked those relays to make sure they were dry and connected. Thanks for the help.