Well, I got the magnifier out and looked the Instrument Panel Circuit Board over pretty good. All solder joints looked clean and tight enough to give it a try as it was. I then jumpered the light switch harness connector on the appropriate terminals and everything on the IP (minus Speedometer and Odometer), and all other lights in the dash area turned on. I ordered a light switch. I tested the old switch and the Potentiometer which I suspected to be bad, had variable voltage when operated from Min. to Max. dimming. After I get the new switch, I'll see if I can repair the old one for a spare. It is quite delicate, so I didn't want to chance it for the time being.