They are rarely the cause of a fault on their own, but a cracked cover, a bent bracket or a seized actuator will take a circuit out of service just as effectively as a failed module.
Most of this range is vehicle-specific in shape rather than in function, so the part number on the original is the only reliable reference. Photograph the failed item in place before removing it: mounting orientation and the position of the connector or drain channel matter, and a bracket fitted upside down will hold the component at the wrong angle.
Where an actuator or motor is involved, confirm the mechanism it drives moves freely by hand before fitting the replacement, since a binding linkage will stall a new unit the same way it stalled the old one.
