92 LeSabre headlights just stay on

All of these devices run through a computer control module generally referred to as the GEM (Generic Electronic Module) module, you need the dealer to test this control module with a special scan tool.

The headlight courtesy module is not timing out. The ABS light will not affect normal braking. It is not cost effective to repair and as old as your car is, I would just remove the ABS bulb from the dash.

The fog lamps are computer controlled .the body control module (BCM) will energize the fog lamp relay control circuit. The BCM receives the park lamp ON signal from the interior park lamps supply voltage signal circuit.
DTC B2527 Front Fog Lamps Circuit Low
The body control module (BCM) monitors the front fog lamp switch signal circuit in order to determine when the fog lamp relay is to be energized. When the BCM senses that the front fog lamp switch signal circuit is grounded momentarily by pressing the fog lamp switch, the BCM energizes the fog lamp relay by grounding the fog lamp relay control circuit.

Your best bet , take it to the dealer . Could need BCM replaced , would need to do testing using the Tech 2 scan tool . A new BCM has to be programmed .

Body Control Module (BCM) Replacement
If the body control module (BCM) is replaced, the following procedures must be performed in the following order:
BCM Reprogramming--Refer to Body Control Module (BCM) Programming/RPO Configuration in Computer/Integrating Systems.
Important: This procedure has to be performed only for vehicles equipped with the Passlock™ System.
Theft Learn--Refer to Programming Theft Deterrent System Components in Theft Deterrent. A new BCM will learn the Passlock™ information automatically, but the powertrain control module (PCM) must still learn the theft information from the BCM.

Not a Corvette expert, but I don't think sunlight would have any effect.
The motors should close the doors when you turn the lights off regardless if it is dark or not.
Are the headlights staying on, or just the doors staying up ? The up position is the default when something is wrong, so I think it takes voltage to close them.

Have the LCM (lighting control module) tested by the dealer.

Sounds like you have some confusion going on here.
The dash lights and tail lights have always been on different circuits and fuses. So if one set of lights fail, the other stays on unless the headlight switch blows up.
The fuse marked "instruments" is for the speedo and gas gauge, not the lights.
On your car there is an instrument panel module and a dash integraded module which both involve the dash lights.
You may need a shop manual to get the wiring diagrams and test procedures for this circuit.
Another thing - after 1998 most cars and trucks switched from having the headlight switch provide power to having them provide the ground connection.

The first thing the dealer would do is diagnostic's . Would not guess and just replace the BCM . Hooking up the factory Tech 2 scan tool an checking for DTC'S - diagnostic trouble codes , input data to the BCM etc.
(I have reason to believe the BCM in my 2000 LeSabre is bad ???? )you have no clue ! The BCM has nothing to do with gauges , insturment cluster ! Beside's you still would need to take it to the dealer because it would need to be programmed .
Leave this to a qualified repair shop . Plus the dash doesn't need to be taken apart to replace the BCM . Your vehicle actually has three modules for the body control system .
The body control system consists of 3 modules:
• The dash integration module (DIM)
• The instrument panel module (IPM)
• The rear integration module (RIM)
You have no idea what your messing with . Your best bet ,take it to a qualified repair shop ,and that doesn't always mean you need to take it to the dealer .
Each of the 3 body control modules integrate a number of functional systems under the control of a single module. Each of the modules is connected to the Class 2 serial data line. Many control signals are implemented by Class 2 messages.
Important: The air bag indicator light may remain ON after the DIM module is replaced, and during the programming procedure for the DIM, until after the procedure is completed and the ignition key is cycled OFF and ON .
• Before replacement, record the personalization settings to transfer to the new module (if they are available).
• After replacement of the DIM, perform the following procedure.
• In order to reprogram the DIM, perform the following procedure.
Using a scan tool, preform the New VIN Procedure.
Perform the Setup SDM Serial Number in DIM Procedure.
Using the scan tool, set the Point of Sale in the DIM module to the correct country.
Using the scan tool, configure the RPO option configuration.
Perform the vehicle personalization in order to reset the owner's desired personalization settings. Refer to Instrument Cluster, Gauges and Console.
Plus power door locks and windows are controlled by door module system , not body control system .The vehicle is equipped with power door locks. Each lock actuator is powered and controlled by the door module mounted in the individual door. The driver door module (DDM) is the master control for the door lock system but the rear integration module (RIM) contains the program that determines when the lock functions are permitted.
Mess with the wrong stuff an you will render your vehicle useless
cost to much to fix.

There is no relay.... there is a "Lighting Control Module". Its above the fuse box. Its hard to tell you what to check, without a wiring diagram, but if you disconnect the headlight switch and they go out, I would guess that the switch is bad, if you disconnect the switch and the lights stay on, then I would say the module is bad. But I would get a wiring diagram and check fully before spending any money on a module.

do you have a secuity light staying on?