Does the ac charge unit fit all types of vehicle low side service port?

No, the AC charge unit may not fit all types of vehicle low side service ports. Different vehicles may have different sizes and types of service ports, and the AC charge unit may not be compatible with all of them. It is important to consult the vehicle's service manual or specifications to determine the correct low side service port size and type for the vehicle in order to ensure the AC charge unit will fit properly.