When I bought the car it had a goodwrench alarm system already installed. I've never had a problem with it, until I ran into issues with my battery not charging. When the battery is dead (not completely but enough that the car won't start) the alarm system gets super sensitive. Just touching the car will sound this obnoxiously loud alarm. Puttting the key in and turning it isn't enough and it blocks me from starting it. I found a button and a switch under the dash and when you press the button with the key turned the alarm will go off. I noticed that the switch is to turn the alarm off because when I flipped it the red blinking security light goes out.....but the alarm system will still go off from the slightest touches on my car. I wouldnt bother with it because it only happens when my battery is dead but I'm trying to fix the battery issue and having it sound this deafening alarm every couple of minutes is annoying and probably pissing off the neighbors. Plus the last thing I need is the cat to walk on it and set it off in the middle of the night

 

I would say if you don't have or can't find a schematic or owners manual for the alarm, pull it out. Many of them are the simple one two or three wire hookups. They just have you install the power and ground and then tap into the door switch, maybe trunk switch, maybe headlights and possibly ignition. unless you really like tracing wires and doing amp draw tests. The alarm could be causing parasitic and draining your battery anyway.

 

I temporarily disconnected the siren while I was working on mine. Also, if you press the button on mine with the ignition in the run position for 5 seconds it goes into valet mode. Good luck.