Could a fuse cause the drivers door on 2001 Honda Civic EX not to lock either manually or with an automatic locker?

A blown fuse is unlikely to cause the driver's door on a 2001 Honda Civic EX to not lock. The door locks are typically controlled by an electrical system, and a blown fuse would prevent power from reaching the locking mechanisms. However, if the fuse is blown, other electrical components in the door, such as the power windows or interior lights, would also be affected.

More likely, the issue is with the door lock actuator or the door lock solenoid. These components are responsible for physically locking and unlocking the door, and they can fail due to wear and tear, corrosion, or damage from an impact. If the door lock actuator or solenoid is faulty, the door may not lock properly, even if the fuse is intact.

To troubleshoot the problem, you should inspect the door lock actuator and solenoid for any visible damage or corrosion. You can also try to manually unlock the door by using the key. If the door unlocks manually but not with the electric lock, then the problem is likely with the actuator or solenoid.