i'm thinkin that the ignition wire under the column was spliced into for the alarm as .. some are done this way as a type of anti-theft system.

whats the history on this alarm & who put it in.. check your wires comming off the key switch.. there are about 4-6 of them.. make sure nothing is grounding it self out either.. this could cause power loss of the battery or shorting of the battery... good luck