Using the ARB wiring harness with a switch Pro or SPOD May 09, 2019The problem I found was with the ARB wiring harness. The wiring harness itself is quite complicated by design and out of necessity. It was designed to hook up the compressor with a pressure switch and run multiple solenoids for front and rear air lockers. ARB Air Locker Wiring Diagrams - Offroaders The ARB Air Locker is a unique air operated unit, for which the locking action is controlled by the driver with a push of a button inside the cab. A 12-volt air compressor (24 volt also available) engages the unit in approximately 1 second and can be engaged at any vehicle speed. 100% drive to each wheel when the unit is locked up.