What is the Relay part number for compressors? May 26, 2023 20:49 Relay part number: 180905SP This relay is compatible with ARB Single, Twin and Portable Compressors. Related to Compressor Related articles What wiring harness do I need for Onboard Compressors? Compressor components What pressure switch is needed for onboard twin compressor? Do you sell refurbished air compressors? What is the best Air Compressor for me? Comments 0 comments Please sign in to leave a comment.