I got the headlights off but I think I need to change the high beam switch on the column connected to the turn signal stalk. Also I can't find a 1989 dimmer at the store. I got one out of a 1991 trans am. I had a 1989 firebird. They had the same headlight and dimmer switches as my wrangler except for how they mount to the car.There are two styles of dimmer switch possible on a YJ (Or early XJ)
If the switch has four wires, there is a "Flash to pass" function in it where it will turn on the headlights momentarily when you pull the switch back. The four wire switch has an external Battery + power feed. It might be stuck on if the main headlamp switch is turned off and the lights stay on. These usually came on high line models like the Larados or Limiteds
Four wire switch:
A base model may have the three wire switch, without the flash to pass, and then, it gets fed power only when the headlamp switch is turned on. in this case, suspect a short in the headlamp switch.
Three wire switch:
Hope this helps!