Why my interior lights won't work in my 1991 Cadillac brougham?

If the interior lights in your 1991 Cadillac Brougham aren't working, it could be due to a blown fuse, a faulty door switch, or a problem with the wiring. First, check the fuse box for any blown fuses related to the interior lighting. If the fuses are fine, inspect the door switches to ensure they're functioning properly, as they can prevent lights from turning on when doors are opened. Lastly, examine the wiring for any signs of damage or disconnection.