At a glance, the problem with the driver's headlight yells at me "faulty ground splice in the headlight!!!" Quick check (to determine if fault is in the light, or elsewhere in the car):
Because you still have the OE lights, plug that in, and see if it functions normally.
"Lights broken, but work after monkeying with the switch": That one tells me "switch is dying, and needs replaced." Yes, people will tell you "troubleshoot!!!!" But, generally, when playing with a mechanical switch causes normal operation to resume, the switch is the cause of the malfunction. And, after 20 years, and nearly 300,000 miles, it's not out of the question for the switch (any high-load mechanical switch, for that matter) to just start dying.
Because you still have the OE lights, plug that in, and see if it functions normally.
"Lights broken, but work after monkeying with the switch": That one tells me "switch is dying, and needs replaced." Yes, people will tell you "troubleshoot!!!!" But, generally, when playing with a mechanical switch causes normal operation to resume, the switch is the cause of the malfunction. And, after 20 years, and nearly 300,000 miles, it's not out of the question for the switch (any high-load mechanical switch, for that matter) to just start dying.
