You can also try slkworld.com

I don't have direct knowledge of these cars, but based on 1997 era cars, the fog light switch only sends a signal to the body computer then a relay or transistor is triggered turning on the light.

If relay, it might have stuck and could be cleaned, if transistor replacing the body module is a more direct route unless you have electronic and soldering background to diagnose and repair.

In any event, be sure to post the results here to help others in the future.