The Compressor And Relay
All of the compressors are sealed for moisture and dust resistance so they can be mounted anywhere on the vehicle. It is OK to mount it underneath the vehicle but keep it inside the framerails away from water and debris thrown off the tire. Use the rubber grommets supplied on the feet of the compressor to reduce vibration. A main power wire of 12AWG or larger will be needed to supply each compressor. It will attach to the red wire on the relay. The yellow wire on the relay will go to the red wire on the compressor. The black wire on the compressor should be attached to a clean ground, usually the frame.