cooling fan problem

Hey guys my sister has an 01 cavalier and the cooling fan wont shut off. she said she heard it running last night and came out this morning and the battery was dead, i went and boosted it and the fan automaticaly came on then continued running till the battery died again. anyone have any suggestions on what this could be.?

Thanks

Bad fan relay. Not entirely sure where its at on different specs of cars, so just trace the wires. Or be nifty and wire it up to a switch in the car (fused, of course).

, so just trace the wires.

Paying close attention fo rone that may be stripped and grounding out or shorting to power.