What do you mean by the siren blinks? The front and rear lights normally flash once for unlock, three times for lock. If you have the siren that 'chirps', it'll chirp once for unlock, three times for lock. If you have the mod for the chirp (radio shack siren wired into the fuse panel under the hood), the 'chirp' will come from that area and not from the siren location.
If the siren is making a cricket sound when it chirps or activates, you need to either replace the siren or replace the 2 internal rechargable batteries IN the siren that are soldered to the circuit board.
OK, my turn, I've read (I think) every post on the car alarms. I have 05 Roadster, and I got up to pee the other night, glance out my kitchen window and my lights are flashing. So unlock and re-lock the doors. Lights stop. Go back to bed, figured maybe cat set off alarm. BTY, no alarm siren. So go to VA hospital yesterday in Orlando, doctors appointment. Put top, close window, left car set my alarm/lock doors. Spend 3 hours there came out and the lights are flashing, figure someone might have bumped the car. Long store short. Same thing this morning, pee, check lights flash. Unlock/lock doors lights stop. Decided to leave unlocked. Been finding and read post since 2:30, now 4:45, my question to you experts, if I remove the alarm mod., will the car still operate without it? Will the car doors lock/unlock? I'm the 3rd owner, I'm guessing that it has never been changed and the previous owners never had a problem with it. I also figure that the batteries in the alarm are shot, because no siren. If the car will operate with out alarm mod., I may just pull it and not replace it. And if someone steals it(wishful thinking), then my insurance company has to pay. I love the car, but it has cost me nothing but money since I got it (1 year now). Whole new ignition system (key system), 2 hydraulic cylinder rebuilds, and now this, hard to enjoy a car, when your worried about it leaving you setting on the side of the road. So enough complaining, can the modular be removed and the car still function? This enquiring mind wants to know. Btw, great forum, help me on a lot of other areas, especially with the hydraulic top system and new license plate lights.
PS: new FOB batteries, 2months ago and the battery in the car says it was installed 5/15. Will get it checked for proper charge and volts.