Originally posted by The Dude
if your alarm's accesory function is (-) then you cant hook the solenoid directly to the alarm brain right? You'd have to use a relay with a fused 12 volt?
yup...
most alarms may require a relay either way though, as its only a transistor output, which is not capable of much amperage, and the solenoid usually draws more than the output is capable of handling.