ActronAir Expansion Module Connectors are the replacement connector hardware for ActronAir outdoor PCB expansion module interfaces, providing the physical and electrical connection between the main outdoor board and any expansion modules fitted in the control box. Damaged or corroded connectors cause intermittent communication faults between the main board and expansion modules, which can present as unexplained fault codes or erratic system behaviour. Isolate power at mains before replacing any PCB connector components.