lights come on even though they are turned off.

You have a defect in the lighting control; maybe an electrical short in the light switch.

In 1992 these has a control system that used modules to control the light modes. Chances are high that the park light control module is messing up. The problem is getting parts to keep it stock. If your shop can’t find any you need to consider a rewire of the headlight/park light system to go with a full manual control.

the sentinel switch could be on. that could cause what you describe.