instrument cluster won't dim

I did a search. to no avail.
My panel (lights) won't dim, it's either hi or off?
any thoughts?
it's a '93 4.0L 4X4 with full gauges.
thanks

The headlight combo switch is bad. There is a rheostat that is built into the switch and when you twist the knob it varies the resistance. The winding has probably broken and you only complete the panel light curcuit in the full on position where the fixed contact is in the pic #5

http://en.wikipedia.org/wiki/Rheostat#Rheostat

so just find a new one at the yard?

Sure, they are easy enough to change that if you get a bad one, or a short-lived one, at the salvage yard NBD.

Go to rockauto.com and search the part number for your 93, then check and see how late of a year the same part number is used--that will give you a range of XJs to consider for a source.

Good luck.