You might try replacing the ignition switch. My old Ranger had similar problems.
Ford had a major recall on the ignition switches several years ago. With age, they
would start to open up, causing a lost of contact and power to various electrical
instruments and circuits. The switch cost about $20.00 and the bolts holding it
on the column have to have the heads drilled off to replace the switch and new
bolts. It was't a bad job, if you are handy with your hands. I will try that before
spending a ton on money for someone hunting for the problem. | 
