2004 Lincoln navigator interior lights don't come on when unlock. Sometimes auto headlights don't come on, seats don't move. Liftgate won't open until vehicle is started. Is this a relay or fuse?

. When you open the door or just unlock the door the lights don't come on ?
Vehicle Security Module The vehicle security module receives inputs from the following:

• door ajar switches
• keyless entry keypad
• ignition switch
• remote keyless entry transmitter

The vehicle security module uses these inputs to control an output signal to the instrument cluster which controls the battery saver relay and courtesy lamp output.
Interior Lighting Systems The instrument cluster grounds the battery saver relay and supplies the power for courtesy lamps when any door ajar switch is opened, or the interior lamp (headlamp) switch is closed. The instrument cluster then supplies voltage to the interior lamp circuit. Vehicle speed must be less than 24 kph (15 mph) for the instrument cluster module to keep courtesy lamps on. The interior lamps will remain illuminated for up to 25 seconds after all doors are closed unless the instrument cluster module receives an input from any of the following:

• voltage from the ignition switch
• a vehicle speed signal
• input from the keyless entry keypad through the vehicle security module
• input from the remote keyless entry transmitter lock or panic switch through the vehicle security module

Do you know what body control system DTC'S - diagnostic trouble codes are ?
Instrument Cluster Diagnostic Trouble Code Index DTC Description Source Action B1342 ECU is Defective Instrument Cluster REFER to Section 413-01 . B2499 Courtesy Lamp Output Failure Instrument Cluster Go To Pinpoint Test A . B1320 Driver Door Ajar Circuit Open Instrument Cluster Go To Pinpoint Test A . B1328 Passenger Door Ajar Circuit Open Instrument Cluster Go To Pinpoint Test A . - All Other DTCs Instrument Cluster REFER to Section 419-10 .
Principles of Operation
The autolamp system provides light-sensitive automatic on/off control of the headlamps and parking lamps controlled by the vehicle security module when the headlamp switch is in the autolamps position. When the ignition switch is turned to the RUN or START position with the autolamps feature already enabled and the ambient light level is dark, the vehicle security module will request the headlamps and parking lamps be turned on. When the autolamps are disabled, the vehicle security module will request the headlamps and parking lamps to be turned off, regardless of the ignition switch position. When the vehicle security module has turned on the exterior lamps and the ignition is turned to the OFF or ACCY position, the exterior lamps will remain on for an additional time specified by the customer or the headlamp switch is turned off.
When the autolamps have been enabled and the ignition switch is in the RUN/START position, the vehicle security module will request that the exterior lamps be turned on or off based on ambient light level. If the vehicle enters darkness for at least 15 seconds, the vehicle security module will request the exterior lamps on. If the vehicle enters light for at least 15 seconds, the vehicle security module will request the exterior lamps off. By delaying turning on and off the exterior lamps during short periods of darkness and light, the vehicle security module prevents the exterior lamps from flashing on and off.

• The autolamps are inoperative - do not operate correctly

• Circuitry.
• Photocell.
• Headlamp switch.
• Vehicle security module.

• Go To Pinpoint Test G .

Power Lock
The power lock/unlock feature requests all of the vehicle doors, including the liftgate, be locked or unlocked upon a customer request from any interior door lock switch in the vehicle. The power door locking system functions independently of ignition status or vehicle speed. When the vehicle security module receives an unlock/lock command from any door lock control switch, the vehicle security module will activate relays internal to the module to supply the correct power and grounds for the door lock actuators.
Your best bet , take it to a qualified repair shop .