The car was running when the East Orange student slipped while working on the front bumper and cut his wrist on the fan blade around 11:20 a.m., the authority's Joseph Pentangelo said.
He ended up with "a deep cut to his right wrist that caused an arterial bleed," he said.
Authority police applied a tourniquet before an ambulance took the victim to Hackensack University Medical Center, Pentangelo said.
Click here to follow Daily Voice Ridgefield Park-Hasbrouck Heights and receive free news updates.