In case anyone else has this combination of symptoms, I have discovered the cause and made a repair.

For the past month I have occasionally smelled a burning/melting plastic smell coming from the center vents. I didn't know where it was coming from, but with no smoke or fire, I simply ignored it. Plus I have too many other things that I need to tend to on this car.

Then yesterday when I switched on my headlights, the dash lights did not come on and neither did my headlamps, so I switched to running lights, and the dash lamps came on along with the running lights. I did a little searching and found reference to the main headlamp relay under the hood near the coolant overflow tank, and a vague reference to another relay behind the center console. I wiggled the connections to the relay under the hood but it made no difference. I checked the ground wires near that relay and tightened them but they looked excellent anyway. It made no difference.

Then played with the headlamp switch a bit and could hear a clicking relay behind the center console when twisting from running lamps to head lamps and off again. I removed the center console and then it all made sense. The wire connector leading to the left-most relay behind the top of the center console was melted and blackened. In particular, the main large socket on the 5-prong connector had not been making good contact and had overheated and eventually stopped making contact all together.

I removed that relay, opened it and gently rubbed the contacts inside to make sure it was clean, the closed it back up. Then I sanded the prongs of the relay with emory cloth the stuck a small screwdriver into the sockets in the connector to scrape as much oxidation or whatever crud was built up in there. Then I gently squeezed the troublesome socket connector with some needlenose to make better contact with the relay prong.

This not only fixed my headlamp problem, but no more burning smell. Funny thing is that I cannot locate this relay on any parts stores. I don't need a new on, but if I did it was not obvious to locate.

Hope this helps someone else in the future.

-Chris