LED Wiring

I've got an LED that has a blue and red wire off the two posts - which is pos/neg? With a +2v output from the alarm, does the negative need to go to chassis gnd or to the gnd when activated? Thanks.

Most cases, the red is power and the blue would be ground.  You can test it though with a AA battery to be sure.  As for where to hook it up, I'd say ground when armed so it's only on when the alarm is armed.  That's just my opinion I could be wrong.  Then again if I am I'm sure someone here will correct me.Cause I'm So white and nerdy...

First Class Certi-fried installer

Thanks for the information. That's what I was thinking, but I wanted to make sure that there wasn't anything unusual about it. I was under the dash of my truck the other day, found an alarm poorly installed (previous owner) and decided to fix it. Pulled it out to re-wire and couldn't remember the LED wiring. That combined with my previous frustration of having a bad relay and assuming it was good has really drawn this project out.