Job’s done!
Teased the door switch out of the jamb ~ careful not to break that brittle plastic! You can see that a previous someone already broke off the retaining tabs :-/
Carefully disassembled the switch. Looks like each of the three connector pins go to one of the three “tulip” contacts. When the door is openned the spring-loaded plunger extends, allowing the copper washer to meet all three of the contact ends and shorting them together. This activates the courtesey lights, key buzzer (if key is in the ignition) and “Light’s On” warning buzzer and LIGHT dash indicator (if the lights are not Off).
My contacts were intermittant, and I found them to be barely making contact with the copper washer. I spread the ends of the “tulip” a little bit so they made good contact when the switch plunger is out. Don’t get carried away - you don’t want them contacting the washer along thier length, only at the ends.
Buttoned it up, reconnected it, and tested it out. Works like a champ! Buzzer now functions properly for my lights and key warning - it was very intermittant before (I would only get a quick “bzz” when openning the door).
Unfortunately, my LIGHTS lamp is still not lighting. Which sounds like a good excuse to relamp the entire dash! I’m pretty sure I have several burned out bulbs. Maybe I’ll even look into switching over to LED. Hmm…