help installing alarm wire on civic 99 ex

I installed a remote start in a '97 civic.  For the tach wire, I grabbed the blue wire behind the tachometer on the dash.  To me that was easier that going through the firewall.  Just a couple of screws, and the gauge cluster pops out ( you don't need to take it out all of the way)....and then behind the tachometer there's a blue wire.  I stripped it a little, and then tested it with a DMM to make sure it was correct, and it was....so I used it.  I'm not sure if it's also in the little mess of wires that's behind the driver's knee panel (about where your left knee would be), because I also found the parking light wire back there.  JUST BE CAREFUL, because I think the yellow wire back behind the tach might be the airbag, so take all airbag warnings (I don't know what they are).  Some say to disconnect the battery, some say that could possibly set it off when you put them back....I just didn't mess with the yellow wire back there, and I was ok.