I need help w/after market remote start

I just purchased a 2001 Mercury Sable. I LOVE evrything about it but it has an after market remote start that won't work. It is an audiovox (elvatoc?) APS2K4SAW. When you push a button the light blinks rapidy. I replaced the 27A battery and the same thing happened. There is another battery like a watch battery but it does not appear to be removable. If I had a manual or even knew who sold them I could move forward. With leather seats and no seat warmers, I would really like to get this thing going. It could possibly have been purchased at Mickey Shore? I would appreciate any help you could give. Thanks!