Here the situation:

When I depress the brake the bulb warning light comes on but all three brake lights come on. When I turn the headlights or parking lights on the bulb warning light goes on without the brake derpessed. When I depress the brake pedal when the parking or headlights are on the left rear brake light goes out altogether (its on before than - on one of the single elements I assume) I also seem to hear a louder noise in tha car that I recall when what I assume is the brake light relay closes/opens.

I've tried cleaning the contacts of the bulbs, checked the grounds from the rear light assembly I've switched the brake light bulbs between left and right and have the same problem (still with the left rear brake light).

Looking for ideas given this specific combination of symptoms. My guess is still a bad ground a bad relay or perhaps a short but I'm no electrical genius.