How to desensitize my car alarm?

April 4, 2007 2:47 PM

How do I turn down my 2005 Corolla's alarm sensitivity or turn it off completely?

My alarm is too sensitive and I'm afraid of bothering the neighbors when it goes off while I'm not around to turn it off with the key fob. How can I turn down the sensitivity or disable it without having to go to the dealer (far away and always overcrowded on the weekends)?

The car is a 2005 Toyota Corolla. I had the alarm installed at the dealer and I don't think this is a factory alarm because it gets tripped from all sorts of random things happening OUTSIDE of the car with all the doors closed and locked.

Things that set it off:
- people who drive by and rev up their engines
- loud busses
- a big branch from a fallen tree getting blown into it by the wind

A co-worker took a look under the dash at the alarm to look for the little dial you turn to tune down sensitivity, but couldn't find it. I'm not sure what the alarm's manufacturer or model number is.

Does anyone have any suggestions on making the alarm less sensitive or turning it off completely?

posted by nakedsushi to Travel & Transportation (9 answers total)

It's been almost 10 years since I installed a car alarm but to the best of my knowledge they haven't changed notably. There's a sensor that may be on board the car alarm "brain" or it may be external. It should have some sort of tuning device on it which may be a big ol stalk or may be a tiny little potentiometer that you need a jewler's screwdriver to adjust.

Here's my suggestion after all that - why not simply disable the horn? The reality is that nobody looks twice at a car with its siren blaring, what really makes an alarm useful is ignition cutoff. Without the annoying horn the alarm can continue to sound randomly but without irritating everyone around.
posted by phearlez at 3:19 PM on April 4, 2007

Response by poster: phearlez: I don't want to disable the horn beause I still use it sometimes when I'm on the road. Waving my fist with an angry frown on my face doesn't seem to scare drivers who cut me off away.
posted by nakedsushi at 3:22 PM on April 4, 2007

I think he's referring to the alarm's connection to its noisemaker.
posted by rhizome at 3:25 PM on April 4, 2007

Oops - clear in my head, not on paper. The car alarm itself will be in a little box about the size of a paperback and probably is under the dash though it could be in the engine compartment near the horn. There will be a small hole or little stalk on it to adjust the motion sensor on it or possibly on another small little box the size of a ring box, attached to the 'brain' with a cord.

Will be assuming that's how the adjustment works. A quick look at the website of the company whose alarms I have installed in the past shows that their cheapest model seems to have no adjustments (or they are only indicated on the install guide which is not online) and the more expensive one has an electronic adjustment.[pdf, page 38].

Is there any company name on your remove dongle?
posted by phearlez at 3:26 PM on April 4, 2007

rhizome - perhaps the alarm uses the car's horn as its noisemaker. In which case it might be possible to decouple the alarm from the car horn but... maybe not.

I would never suggest you completely disable your car horn - you need it to pass safety inspection in some states.
posted by phearlez at 3:28 PM on April 4, 2007

Response by poster: phearlez I've seen the alarm box the other day while a coworker was helping me out, but we couldn't find any type of adjustment hole or stalk. Coworker thinks it must be an electronic adjustment. I don't have the manufacturer name with me right now (stupidly forgot to look for it when I had the box out), but I like our idea of unplugging the horn from the box.
posted by nakedsushi at 3:29 PM on April 4, 2007

Do you not have a little bauble that locks and unlocks the doors? Doesn't it have a name on it?
posted by phearlez at 4:01 PM on April 4, 2007

Response by poster: Oh dur, yes I do. The top says "TRW"
posted by nakedsushi at 4:07 PM on April 4, 2007

Unfortunately googling turns up nothing on that brand, probably because of the overwhelming number of references to the credit people TRW. I did find some mentions that might indicate the alarm is likely made special for the manufacturer - you didn't receive any sort of manual with it, or there isn't already a section/insert in your car's manual for it?
posted by phearlez at 6:08 AM on April 5, 2007