Y would someone pull a a/c fuse out?

I just bought a 1997 astro for work car... and the a/c doesnt work,,,the controls are stuck on defrost...also no cold air.. after lookin i realized that a fuse had been taken out.. the fuses under the hood. before i replace it y would someone do this? pre owner says huh i didnt do it! well oook... really dont wanna put too much money into this but help!!!!!!!