When diagnosing 2005-2015 Volkswagen vehicle generators equipped with a one-way clutch, it is recommended to first verify the operation of the one-way clutch located in the generator pulley before replacing the generator assembly.
Remove the belt from the generator pulley and use a trim removal tool to hold the fan blades inside the generator. When attempting to turn the pulley by hand with the fan blades held, the pulley should spin freely in only one direction. If the pulley spins freely in both directions, the one-way clutch has failed and should be replaced before continuing diagnosis.
