My '92'* "Illuminated Entry System" and "Interior Courtesy Lights" quit working. The lights do not come on when you lift the door handle, open the doors or turn the head light **** completely one direction. You can turn the lights on with their individual switches.
What'* the cause and how do I fix it?
Thanks!

Check the fuses under the dash - I believe it'* fuse 15 on your car.

The fact that your headlamp switch will not turn them on confuses me. Can you try that again? Rotate it until it clicks.

Do you have lights around your door lock key hole on the outside of the car? Are those functioning properly?

If it is not the fuse, you may have lost a ground connection somewhere.

Mine only work when it'* dark outside. Light sentinel.
It is a design feature on the newer Bonne'*. I don't know if yours has that feature or if you mean that they never come on, day or night.

This is a weird one. The lights can be turned on via their individual switches since they are getting power, and the individual switch is a second ground path that allows the local bulb to light up but not the common ground circuit that ties them all together. It'* why the common ground circuit isn't working that has me kind of stumped here. It goes to all four door pillar pin switches as well as the headlamp switch.

Hey, waitaminnit here: Your car will kill the interior lamps if they're left on for more than 10 minutes (e.g. if you leave a door open, etc.) So if one of the door switches shorted itself to ground, that would turn on the lights for 10 minutes, after which the circuit is turned off by the computer, and stays off until it detects that the door is closed again. Since it'* a shorted ground and not a door left open, it never resets itself.

Try disconnecting the battery temporarily, then reconnecting it, and see if the lights come on inside. If so, you have an interior light circuit shorting itself to ground somewhere.

Yeah, but the headlamp switch bypasses the RAC module, that'* why he needs to check it again.

Thanks for your replies. Here is an update.
The Courtesy Lights now work when I rotate the head light switch. Maybe the contacts were dirty. They do NOT work when I open the door from the outside nor does the outside illuminated key lock light up.
How many switches are in the door? For instance, if I try to exit with my head lights on, I get an audible warning. (This has always worked, by the way.) This can be shut off (besides shutting the door) by manually rotating the door latch to the closed position. As far as I can tell, nothing else moves when I do this (as in the latch actuating mechanism). With the door shut, just lifting the outside handle (without actually opening the door) used to turn on the courtesy lights and illuminate the key lock. This car doesn't have Light Sentinel but it seems like it would only turn these lights on when it was dark. Are these previously described features controlled by two separate switches in the door?
Also, as someone stated, after 10 minutes it would shut off courtesy lights and the radio if the key were in the off position. If you opened the door it would shut off the radio immediately. (I'm sure this is true but I might be confusing it with my wife'* '99 Bonneville. PS The '92 is a much better car, quieter, drives better, less wind noise by the front door, front lower corner window seals (next to the outside mirrors). Anyone else have that problem?)
On the dash about 3" behind the VIN number plate is what looks like a recessed button. What is that?
Thanks!

OK, we are progressing.

Have you had any aftermarket alarms or engine starters installed on the car?

Do this for me... Wait until it is dark outside and try pulling the handle (when it is locked) on both the passenger side and the driver side. Tell me if either of the lights around the keyhole are still working. They are hard to see in the daylight.

This car never has had any aftermarket electronics installed.

The lights around the key hole don't work on either side, nor do the courtesy lights come on when the handles are pulled with the doors locked.

Next?

OK, I think that your RAC module or the wiring to it has gone bad - Let me check something and get back to you.

OK, there is an illuminated entry input test. Do the following:

Disconnect the RAC module.

Turn the ignition to run.
Test the orange and pink/black wires for 12V+. (A & B)
Connect a test light across the pink/black and black wires. Light turns on. (B to G)
Connect a test light across the pink/black and white. Light on with any door open. (B to C)
Connect a test light across the orange and grey wires. Light turns on when front door handle lifted. (A to K)
Ground the dark blue wire. You can do this by jumpering the dark blue to the black wire. The interior lamps should turn on. (J to G)

Do you pass all of these tests? Then you can pretty much be guaranteed the RAC module needs to be replaced.