Why dose the fuse keep blowing when air turn on

Something is drawing too much current , or something that doesn't run all the time comes on an shorts . What fuse ? A main power feed to the Mall (BCM) ? What make , model an year GM vehicle ?

If fuse keep blowing up, there is a short on the wiring for that particular fuse.
Check the cover on that fuse box and it will normally tell you what number that particular fuse location.
Check your manual of your vehicle and it will tell you what device/comporent is connected to that fuse. Once you figure out what device/component is connected to that fuse then you can start your diagnosis on that particular device/component.

For example, there is one particular fix I've done which the fuse keeps blowing.
I've checked the location of the fuse and check the users manual for that particular fuse and it indicates a cigarette lighter. I've check the cigarette lighter and there was a coin stuck inside the hole which causes the new fuse to blow. Once the coin was removed, the fuse did not blow anymore.

the out put of the alternator is wrong at 18.9 volts
it should be at 14.5 to 14.8volts maximum
the high voltage will be making high current flow and that will blow fuses
have the alternator bench tested and check the regulator as well as the regulator controls the voltage.

check the wiring from the fuse to the pump for broken insulation that is earthing out the wire and causing a dead short. Check for screws .pinched wires under mounts, melted wires on exhaust, shorting out in connections.

Year make and model, and which circuit does the fuse protect ?

you need to diconnect the lights then replace the fuse turn on the light switch. if the fuse dose not blow you have a bad light. if it blows . look for bear wire.

you have a short somewhere, installed any new radios or electronic devices lately, which fuse keeps blowing, what dose it power.

We had the same problem but when we put in a new fuse it smoked. It turned out to be something with the master cylinder and required the changing of a 20 dollar part by the mechanic and problem solved

trace the wirring.dose the power for that fuse go to something else? you need a wirring digram

have you checked the fuses? there should be a fuse block inside the cab and another inside the engine compartment, refer to owners manual for exact location,