CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Alarm going off in my 03 lincoln town car

Hi,

my car alarm keeps going off for no reason in my 2003 lincoln town car. Goes off about every 8-9 days, usually at night??

Any ideas?

Thanks, Patty

Will this happen at other places and times? (maybe the alarm is doing its job) Are you having any dome light or “door ajar” problems? Does your alarm have a “shock sensor” is it possible to lower its sensitivity? Is your battery maintiance up (no corrosion) Factory alarm? no possibility of a aftermarket alarm installation wiring failure?

My 95 Ranger does the same thing, if I lock it with the power locks (that arms the system). Horn invariable starts honking at 2AM. Is it the same factory horn-alarm?

A bit of wild guessing here regarding a couple of possibilities.
One is an erratic hood switch which lets the car know if someone is prying the hood open. Body panel fit is altered over time due to movement of the car and miles. This panel movement is normal and can lead to the switch teetering on the edge so to speak.

Another possibility is the anti-theft switch in the ignition switch. This is called a “jiggle switch” and these can also become errratic in operation.

Even gusts of wind can shake the car and set them off. Neither one of those may be the problem but it’s something I would consider looking at as a first step. And testing them may not be so clear cut either. Hope that helps.

You might want to take a look at Edmunds Car Space forums.com
Take a look in there for similar problems with TC alarm problems.

Those darn squirrels! I have a periemter sensor on my car which gets triggered off by stray squirrels. You have the same choice I had: either turn the alarm off and hope the car isn’t stolen or have the alarm sensitivity adjusted and have the same possibilites.
Ya, there really is no good answer.

This is an aftermarket alarm. Did you have it installed or did a previous owner do it.

thanks for you reply. I’m going to check into the battery since it’s almost 5 yrs old now.

yes, same factory horn. Thanks for your reply.

The factory alarm has no sensitivity adjustment and no motion sensing. The most likely causes are:

  1. You or someone else is accidentally hitting the panic button on the remote. This can happen with the remote in your pocket. Try hanging the remotes up somewhere and see if the problem stops.
  2. Car battery problems. If your car battery is the original factory battery, then it is overdue for replacement.
  3. Problems with one or more of the door, trunk, or hood switches.
  4. Electronic problems with the driver’s door module or front electronics module.