Inside each gauge is a tiny nichrome resistance winding on a bimetal strip. When new the windings silk insulation was a pale goldish color and the bimetal was straight as an arrow. 40 years later the winding may be caked with crud to many times its original diameter. Worst examples come from cigarette smokers car. How the tar got to the winding has to do with heat and air movement. Anyway... It cannot be cleaned. You may find the bimetal now has a bow at room temperature too. So the resistance across the gauge can still read the factory spec of 20.2 ohms but not move the pointer as it should. The gauges can be restored but it aint cheap. That little formentioned wire costs me 25 dollars per foot and approx 16 inches is req'd each gauge.
The headlight switch and wiper switch are easy enough to replace without removing the panel.A headlight switch can be purchased new.
Test proceedures to determine a wiper problem to be the switch or the motor cover 3 or 4 pages in a factory service manual. Definately the most complicated electrical system in your car. Bottom line, Clean and visually inspect everything including harness connecters. Replace bulbs, sockets, etc.. that are affordable and cross your fingers.
Good luck
