Final answer:
To tow large heavyweight trailers with trailer brakes, a 7 pole (also known as 7-pin or 7-way) wiring plug is commonly needed to connect all the required functions, including brakes and lights.
Step-by-step explanation:
When towing large heavyweight trailers that are equipped with trailer brakes, a 7 pole wiring plug is commonly necessary. This type of plug is designed to handle the additional connections needed for electric brakes and typically includes functions for lights, turn signals, brake lights, and reverse lights, as well as auxiliary power and connections for the trailer’s brakes.
The 7 pole plug, also known as a 7-pin or 7-way connector, includes the following circuits: Tail/running lights, Left turn/brake lights, Right turn/brake lights, Reverse lights, Ground wire, +12V (battery charge line), and Brake controller output. This provides the necessary power and control signals to operate the trailer’s brakes safely and effectively during towing.