Onboard Air Systems

An air compressor, an air tank, a pressure switch, and the fittings and wiring that join them. The compressor fills the tank, the pressure switch starts and stops it automatically at set cut-in and cut-out points, and the tank holds the air so it is there the moment you need it. Our HornAir systems use a 110/150 PSI switch, meaning the compressor kicks in at 110 and shuts off at 150. That stored pressure is what separates a system from a bare compressor: you are not waiting on a pump while a tire sits flat.

The onboard air system is the heart of any air suspension setup, supplying the air that raises and lowers ride height on demand. It also feeds load support air springs, which is a different job: those add capacity for towing heavy rather than changing ride height. Beyond suspension it airs up tires far faster than a compressor alone, runs air tools for roadside repairs within the compressor's limits, and supplies train horns and air horns.

Match whatever the vehicle already runs. Nearly every pickup, SUV, and passenger vehicle is 12 volts, so the 12-volt systems are the right answer for most people. Heavier commercial trucks, some diesel equipment, and many marine and military vehicles are 24 volts and need the 24-volt systems instead. The two are not interchangeable, and the difference shows up in current draw. Compare it per compressor: a 24-volt HornAir pulls 13 amps against 25 on the single-compressor 12-volt systems, and a dual-compressor build doubles whichever figure applies, which is how the 12-volt 8-Gallon arrives at 50.

A complete system is the safer route unless you already know exactly what you want. The parts have to agree with each other: the compressor has to suit the tank size, the pressure switch has to match the pressure you intend to run, and the wiring has to carry the compressor's peak current. Our HornAir systems arrive with 10 and 18 gauge wire, a wiring kit with a fuse holder, and a standard half-inch push-to-pull fitting, which removes most of the guesswork. Building from separate components makes sense when you are matching an existing setup or need something unusual.

Yes. The same onboard air system is the heart of an air suspension setup and of a train horn install alike, so one compressor and tank can feed both. Two things decide how well it works for you. Tank size comes first, because horns empty a tank in a hurry while the suspension needs air on hand every time you change ride height, so a bigger tank serves both better at the cost of a longer refill. The second is plumbing, since the horns and the suspension each run their own valves and air line, teeing off the same tank.

Start with tank size, because that decides how much air you get before the compressor has to catch up. In 12 volt the 2-Gallon suits horns and light pneumatic work, the 5-Gallon gives noticeably more capacity, and the dual-compressor 8-Gallon is for extended tool use or the largest horns. In 24 volt the HornAir 232 carries 2 gallons at 150 PSI and refills in under 50 seconds. A bigger tank means longer run time but a longer refill.