A cable system for a truck trailer with connectors having a main power connection, a ground connection, and one, two, or more communication cable connections. Connectors include at least a power and ground connection for electrically connecting an individual trailer to the cable system. A master control circuit may be included in the trailer nosebox, and the master control circuit configured to send commands to slave control circuits mounted within the connectors. The slave control circuits in the connectors are configured to receive a control command sent by the master control circuit that may include an address, mode identifiers, or other indications of which connectors in the cable system should take action, and what actions should be taken.