Car alarm goes off at night. UPDATE: Now 3 PM on the clock.

[Boreas]

For about the last 3 weeks now, my car alarm goes off once a night, every day, and almost at the same time at around 9 PM. Im not sure if it has anything to do with the weather getting colder or not. Also to note, once in a while when I drive I will spot the SECURITY light staying on, and will go away maybe after 20 minutes of driving. Its probably related. I was wondering if anyone has any suggestions on why my car alarm keeps going off and what its trying to tell me when the light is on while driving. Thanks!

[Boreas]

Now the light is on everytime I start the car.

[00Beast]

What's the VATS situation on your car? Is it bypassed or active?

[Wes]

Is this a factory alarm, or aftermarket?

And, do you have neighborhood cats that roam? I had a cat that kept setting mine off for a while. Drove me nuts!

[Boreas]

This is the factory alarm. No cats. VATS is active and has not been tampered with.

[olblueeyesbonne]

Which car is this?
My 99 SSEi has done this, although it's only done it 1 time recently that I'm aware of.
What's interesting is when it goes off there is a massive drain of voltage because when the horn honks it barely makes any sound.
Every time the alarm goes off the battery goes dead -I literally got of my 99 the other day, locked it with the button on the door right before I closed the door and then shut it. Got not 10 steps and the alarm went off. Tried stopping it with the remote -no go.
Even turning the lock cylinder in the door wouldn't stop it. Had to wait for the alarm to time out. All was well and the car acted as if nothing happened.

[Boreas]

Sorry, this is the 1997. (Its about to roll 150k tomorrow. :D)

If I knew where the shock sensors were and how to get to them, I could at least check the connections and such. Would this be in a FSM (if one has one?)

[00Beast]

Do these cars have shock sensors? I don't think they do...

[rogers9c1]

my 98 lesabre would do this as it got colder, never really found out why it just kinda stopped doing it. My only guess was that maybe the door switch was acting up making the car think the door was being opened when the alarm was set just a idea.

[trkelly]

Same thing was happening with my 97 SSEi and I had my mechanic disconnect the alarm for the horn only. Everything else still works with the fob just the horn alarm is gone.

[Skippy1827]

Mine did that also. Not sure why. It wasn't all the time. Same scenario, at night.. I ended up having to lock the 4 doors manually from the inside before I got out.
Sold it...

[Mechanical Mike]

Yep, if you manually lock the car then the alarm won't be armed. Your neighbors will love you.

The tamper switch in the trunk lid is known to cause problems. You can also try removing the batteries from your remotes & see if problem goes away. One of our remotes has a hair trigger on the button that sounds the horn.

[Skippy1827]

oohhhhh Mike.....You just triggered my old memory banks...
I do remember that the dealer disabled the switch thing for my hood for some reason. It was so long ago that I don't remember if it was because of the issue you mentioned.
I think my false alarms went away at night then.

[Boreas]

Thanks, that's where I will take a look! Although in the last 2 weeks it has stopped doing it, despite that the Security light is now on all the time. Will update this thread if it fixes the problem.

[Boreas]

Im necro-posting my own topic since this is a continuation of the same situation, and I have an update:

My car alarm goes off at 3:00 PM. Exact time. Every day. I just got an email from one of my co-workers who told me this. They tell me it only goes off for 30 seconds, but its every day at the same time. We also had a really good chuckle because now my car is considered a chime for the office, meaning there's one more hour to go of work, and if I fix it they will no longer know when its ok to go home from work, lol.

What ideas would you have that is causing my car alarm to go off, every day, at the same exact time for 30 seconds? I have tried disconnecting the tamper switch in the trunk, but it still does it. Also, I can no longer pop the trunk with the button on the door, even though I used to. I figured it would be a faulty wire in the door, but why would it go off at the exact time then?

[Skippy1827]

Not sure, but there is also a switch in the hood that I had to disconnect which had no ill-effects on operation.