Q: I have a 2003 lincoln navigator.The drivers fornt door power window does not work. I replaced the regulator, main switch and motor

If the other 3 windows function using their individual door switches but there is no function, for any of the windows using the main driver door switch console, that could be due to the wiring in the driver door having gotten broken at the "flex point" where the wiring exits the door, travels through a short rubber bellows, and enters the vehicle frame. That is a common wire break point. So, check for power TO the driver door switch and make sure the circuit has a good ground, too. If there is no power to the driver door switch, in all likelihood the wire is broken. If you do find there is power to the driver door switch and yet you still cannot get the driver door window to function, please request a power window electrical component diagnostic and the responding certified mechanic will get this resolved promptly. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.