3rd brake light wiring... help

[}{arlequin]

To all the electrical gurus out there,

I've wired an LED 3rd brake lamp to the infamous black wire w/ yellow stripe. It lights up fine when I step on the brakes, but then it also stays "on" when I turn on my headlights. If I tapped the wrong wire, why would it light up when I step on the brakes? Is there another wire in the tail lamp assembly that gets power just from hittting the brake pedal?

Could it be a bad grounding that causes this? Any other wire options that were used for the brake light? Previous owner might have changed the wiring...

Thanks

[RANDY P]

are you grounded straight to metal or to another wire showing ground - w/ lights off? If so -What happens when you step on the brakes AND the lights are on? If the 3rd brakelight shuts off, then that's your problem.

Start over. Take a plain old testlight, grounded to metal and verify you have the right wire, shoot the ground to metal and it should work. Yellow / black is what I used, it's fine on my 81.

rjp