1993 yj jeep from BC.

Wiring, schematic, electrical diagrams, fuse diag,
error codes etc are basic contents of these online books they have here on this website www.reliable-store.com I have attached. Must check it out

Most cars have a headlight relay. It's typically in the fuse box. They do go bad, and often you can pull one out, and smack it smartly, and it will work fine again.

On Google:
Images for 1993 jeep grand cherokee wiring

Short between the rear indicator light and the brake lights.

With a test light follow the wires from the battery to the fuse box to see where you lost the connection. You may have a burnt fusable link. . Run 12 v directly the the fuse box and see if that helps.

Find the pin switch on the front of the drivers side door jam, check the back side of the switch, (near the E brake pedal) make sure the plug is attached. It just plugs in. It is easy to plug and unplug the wiring to this switch on the YJ's so you can drive with the doors off and not worry about your interior lights being on and draining the battery when the engine is off.

sounds like your ECM might be bad. Is there anything else that will turn on besides the lights? It could just be a main fuse. I'd start at the interior fuses if any and then go to the main fuse block and check for any loose wires or blown fuses first.

I also have a 95 yj and mine did the same thing just replace both headlight and it will be fine.
if u look in light and u see a dark spot in the beam then its that light but replace them both anyways not expensive at all..

Probably a bad ground on your front right signal, or a bad bulb. Try switching the right with the left, and see if the problem stays in the same place, or goes with the bulb.