Its main purpose is to connect the truck's factory chassis wiring to a bumper-mounted 7-way trailer connector. It provides the electrical connection needed for trailer functions such as:
Trailer running lights
Left and right turn signals
Brake lights
Trailer electric brakes
Trailer auxiliary/12-volt power
Ground connection
Reverse/backup circuit, where supported
The specific 2020+ Ford cab-chassis adapter listed as ZNA 002-521 plugs directly into the truck's factory wiring and provides a connection for a bumper-mounted 7-pin outlet. It is designed to eliminate cutting, soldering, or splicing of the factory wiring
