hi, and welcome to the world of Eagles, best cars ever made!
Sorry, can't help you at this long distance with switch problems, but, new switches are available. Try APD, or Blasers, I have had to replace a couple of those in my time. Before you spend money, educate yourself, get a TSM (Technical Service Manual) for your car, Usually available on ebay, you may have nothing worse than a a bad wire connection somewhere. Take a deep breath, focus, and start tracing wires from source to end. Sometimes the problem is nothing worse than a bad ground wire/connection. good luck, gz