Fuse at rocker switch is good. Using a voltmeter, found juice all the way to the pigtail going to nav light fixture. No juice at the bulb contacts. Same on both nav lights. Only two possibilities: Bad ground connection (to both lights??) or bad light fixtures (corrosion) but both at same time?? The wiring on this 88 cruiser is prisitine. In fact I hate to be mucking around with it at all. It hasn't been touched since factory. Any other ideas?