On a 1994 Suburban k1500 4wd the air stopped working the clutch is not engaging the fuse by the steering wheel looks ok is there another fuse somewhere?

If the system is low on refrigerant the low pressure switch will shut the compressor down. If you run a jumper wire across the two terminals on the low pressure switch on the dryer ( long silver canister on passenger side rear)you will kick on the compressor and be able to add refrigerant; then it will work.