I have mostly got LED globes on my car, when I wired them up I tested them individually, tail lights.... OK, stop lights... OK. I didn't notice 'till recently that all the parking lights were coming on when the brake lights were on. After a lot of mucking around I figured out the problem. When on "park" all the leds are on dimly and when on "brake" the same leds glow brightly, but a voltage is leaked out of the "park" pin on the globe, hence lighting up all the parkers. A simple diode on the parker wire fixed the problem. I hope this helps others, and saves a few brain cells.
