I have a 2007 trailblazer ls and when I first got it when I clicked lock on my key it would chime that it locked (CHIRP). When I unlocked it it would go (CHIRP, CHIRP). Now when I lock it it wont make a sound but will only lock the doors. Pretty much my alarm isnt working because I tested it out and only the lights will flash when set off, no sound. Please help.