Youd be better off not to use any existing power source to power the alarm. Add a wire from the positive of your battery with an inline fuse at the battery then run the wire inside to a relay mounted right beside your alarm brain.
Then you can splice into the ignition on wire like the one on your amp, or the one on the cigar lighter style plug that is only on with the ignition. Let that wire you spliced into kick the relay on then it will let the power from the battery come through and into your alarm.
Relays are you friend with stuff like this, and they are super easy to hook up they just look a little complicated at first.
I do have a question though. If the power to the alarm goes off with the ignition doesnt that defeat the purpose of the alarm? i.e. alarm will be off when you leave the vehicle? Are you needing an allways hot wire to power the alarm when activated or do you need a wire that goes off with the ignition to activate the alarm? Im not sure on alarms, never messed with any so I dont know....
Last edited by Sunburst Sahara; 02-17-2010 at 02:18 AM.