If it is like my 92 PA, there is a "twilight sentinel" switch that controls the time delay for turning off the lights. Slide that to the MIN position and see if that turns the lights off immediately. If they still stay on, there is an electrical problem elsewhere. If that doesn't fix your problem, spray some wd 40 on the door latches and open and close them a few times, then repeat. My lights stayed on continuosly until I did this to two of my doors. Dirt and grime builds up in the latches and doesn't allow a proper seat for the latch itself.
The spark plug gap for a 1993 Buick Century is: .045 for the 4 cyl 2.2 engine .060 for the V6 3.3 engine
Those systems you mentioned will work normally with the engine off, if you are saying that you cannot shut them off at all then the multi function switch for the lights is faulty or damaged.
There is a switch on top of the steering column dead center. You must have accidently turned it on. It's a parking light.
under the front of the engine about center of the engine. hope this helps
At the lower rear end of the engine
Door pin switch.
On a 1993 buick regal it is on the side of the radiator.
3.8liter, 3800 series 1
1993 BUICK.
On a 1993 buick regal it is on the passager side of the radiator. Hope this helps
newdiv
Bottom of engine, inside the oil pan.