Air compreser location on a 2004 jeep rubicon?

A 2004 Jeep Rubicon doesn't have an air compressor in the traditional sense like you'd find on a vehicle with air suspension. The Rubicon's air compressor, if you're referring to the one for the factory-installed locking differentials, is a small unit integrated into the front axle. It's not a standalone, easily identifiable compressor like you might see on a truck. You won't find a large canister or easily accessible unit.