so i guess i need help on a 3 wire led scanner. i have tried everything and failed. the scanner is either always on or off. i bought the streetglow led scanner and it has 3 wires coming off of it. black= constant ground, yellow = constant power, and blue = to activate the led. they say that the blue goes to the ground on the previous led, but when i do that, its always on. i guess what im asking is there a ground on my alarm system or car that is activated by my alarm and not constant?

 

hook it to your ground when armed output. if you have a starter kill relay you will need a diode to isolate it also.

 

on my alarm, it doesn't have a ground when armed. all the grounds are constant grounds.
i have a blackwidow 2 way alarm.