I had a similar problem on my CJ and found that first, the lights for the dash lights are typically a single orange wire harness connecting the bulbs and grounded via the dash. And secondly, the headlight switch has a very simple dimmer mechinism which is basically a contact touching a spring to create more or less brightness on the dash as the knob is rotated.
My contacts were dirty and the dimmer switch effectivly was not working. I verified that by jumping the orange circuit in the HL switch to a known hot lead (IIRC it was white) and that allowed all the lights to work but killed the ability to dim. I ran it jumped for a while with no problems.
I later replaced the HL switch and found the new HL switch dimmer circuit contacts needed to be cleaned prior to installation to get it to work correctly even though it was NOS.
1980 CJ5 Renegade with 304 v8
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.