installing backup siren

I was told that it was a Crimestopper unit when I bought it off of Ebay. The unit has 4 wires. 2 are +,- and the other 2 are for +,- triggers. When I hooked it up initially it was using the +,- from the current siren which didn't seem to provide it with enough juice so I hooked it up to the same constant 12v feeding the brain and - .This way made it sound much louder so I assumed that this aspect of the hook up was correct. Now when I hooked up the trigger I spiced in to the - trigger being used by the alarm. I don't think the truck has a + trigger. Anyway, When this was complete I reattached the battery and turned the siren on using the key. It started wailing away and wouldn't shut down unless I used the key again. Meanwhile, during my failed attempts at using the alarm remote to shut it down, I could see the led for the alarm responding normally and flasing the parking lights twice as if the alarm itself was shutting down. Only thing was the siren wasn't. What an I doing wrong? This is really getting to me!  Could someone please go to the audiovox website and click on installation manual and tell me what wires you would use to install this siren? I believe I used the brown wire for the - trigger. Thank you in advance for bearing with me. By the way the truck is a 2001 S10 4.3L.

http://www.audiovox.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10001&productid=608&langId=-1

So are you saying that I hooked it up properly based on my description?

On the siren? I believe that they are blue and white plus the norm black & red. I am at work now and can't quite remember the color codes, but I believe blue is - trigger and white is + trigger.

Would this siren place a constant drain on my battery thus killing it?

Are any relays needed in this system to prevent any problems? Please say no.