Headlight switch drama
if you are on the right terminals checking for continuity with the switch in the right positions it's just either good or bad. All of the switches normally open or normally closed contacts don't care what is going on with the rest of the car. Past that with the switch in the car is where the gremlins come in. I will leave it at that and let the real pros help you trace it down. I was looking for an original switch for one of my cars so I will pass the ad on to you. Not knocking any mechanics but maybe get a second opinion on whats going on with the switch hanging in free air to make it easy to check. No fuse blowing?