I'm wondering what could be the cause. I unplug the compressor and it doesn't blow a fuse when the fan is running without the compressor. I think the fan motor is good and I checked a lot of the basic stuff I believe. I have a 67 Skylark.
Over amperage draw on the compressor from lack of oil/freon. Compressor may be starting to go bad/seize up.
Yup. Can you find out what the high and low side pressures are and let us know? Running should be about 180/40, +/-, depending on surrounding conditions.
What car? If it is the compressor clutch fuse, the clutch coil may be drawing too much amperage. You can check the clutch coil resistance ohms to see if it is in spec. You can also hookup an amp meter inline and see how many amps it is pulling. Had that happen on a 91 cadillac, changed out clutch coil to fix it. If it is blowing the superheat fuse for the compressor, refer to previous responses.
Update: Now it blows a fuse even when I unplug the compressor. It basically blows a fuse every time I turn the fan motor on with the compressor unplugged. Thanks again
Does your blower fan still work? It's either bad or there is a short in the wiring. I'd vote for the short, given the short fuse blow time.