There was a recall on 98 jeeps for the wiring behind the dash. Check with the jeep website and run the VIN to see if it was serviced for the recall.
I was provided the wiring to fix the issue on my jeep when I bought it used, the previous owner was just too lazy to fix the issue.
Input your VIN on the toolbar on the left side of the jeep website to check.
If you had already had this done then something might just be lose.