Dash/panel light troubleshooting

On my '75 CJ5, none of the lights on my instrument panel are working. All the lights all the way around the outside of truck work, and the turn signal indicator lights in the speedometer work too. The 3 amp fuse tests out good, but there is no current through the fuse when the lights are "on". Do I have a problem in the headlight switch rheostat through which the dash lights run? How can I test the rheostat? I have a multitester.

I'm sorry to be making so posts today - I'm trying to get my Jeep in good operating order before winter (which starts early here in Wisconsin).

Many thanks.

 

This is from the wiring diagram:



You can test the switch in place with your multimeter, or remove it from the dash. You can remove the switch from the dash by pressing on a button on the side of the body of the switch. The knob and stem will pull out. Then remove the bezel and the switch will be free of the dash.

Sometimes it's enough to twist the knob back and forth a few dozen times to clear corrosion from the rheostat.

Is this enough? Do you need instructions on what to test?

 

I do need instructions on what/how to test if you don't mind.

 

You know how to use a multimeter? There are several tutorials online.

I'd test the voltage at the panel light feed in situ. You can usually sneak your probe in beside the wire in the plug shell to test with the plug in place. If you have voltage at the connection marked "panel lights feed" then you have some problem in the wiring between the switch and the lights.