1998 Jeep Cherokee

you are going to have to get in there with a digital volt meter and start checking wire connections, gorund connections, looking for shorts...the headlight switch itself likes to heat up, melt wires, and cause big problems...if you have access to a meter, and know how to use it, you will also have better luck if you buy a Haynes or Chilton manual, or Factory service manual for your vehicle, to understand what wires to inspect, etc...otherwise you should bring it to someone who can do it, before you have a more serious electrical problem that damages more of your vehicle...ie; battery, alternator, ...who knows...