Car alarm randomly goes off only in one location

Grey_Critic

I have heard of alarms being triggered by rogue signals - I even came across a case of a TV changing channels due to the same thing and that really caused problems in the household.

Back in the 1980s there was a problem with some Rover cars going past Daventry on the M1 - The cars cut out over a half mile stretch - that was traced to a rogue signal from the masts.

jules0621

That's really interesting and perhaps explains why one car but not all go off - if certain cars are more sensitive. Difficult to do something about though, but we'll check out the local area for possible aerials. Thank-you so much.

[Deleted User]

Many years ago i had a Vauxhall (can't remember if it was my Vectra or Astra now)  whose alarm went off randomly and it transpired that the model i had featured a rear window alarm connected to the heating/demisting wiring -  that had got 'worn' over time and triggered the alarm to sound intermittently.

Dealership unable to fix problem, told me i needed an auto electrician (they didn't have one on staff ! ) did some due diligence, found a 'mobile' one in a fairly close location, he came out to me and diagnosed the problem, fixed it within a couple of hours - worth every penny.

basill

Catsacor said:

Many years ago i had a Vauxhall (can't remember if it was my Vectra or Astra now)  whose alarm went off randomly and it transpired that the model i had featured a rear window alarm connected to the heating/demisting wiring -  that had got 'worn' over time and triggered the alarm to sound intermittently.

Dealership unable to fix problem, told me i needed an auto electrician (they didn't have one on staff ! ) did some due diligence, found a 'mobile' one in a fairly close location, he came out to me and diagnosed the problem, fixed it within a couple of hours - worth every penny.

Interesting, from new my company supplied Insignia alarm used to do this, often when the sun got on it.   The garage changed  amongst other things a body control module some wiring and side glass as could detect breakage.   They had it many times under warranty and never did fix it.   I swapped it with a pool car in the end  :-)  

coffeehound

Grey_Critic said:

Back in the 1980s there was a problem with some Rover cars going past Daventry on the M1 - The cars cut out over a half mile stretch - that was traced to a rogue signal from the masts.

The ULF transmitter that communicates with submarines is very powerful.  There's an anecdote that a chicken farmer living near one in the 'States found that by simply routing long wires there was enough induced energy to heat the coops for free

Catsacor said:

Dealership unable to fix problem, told me i needed an auto electrician (they didn't have one on staff ! ) did some due diligence, found a 'mobile' one in a fairly close location, he came out to me and diagnosed the problem, fixed it within a couple of hours - worth every penny.

Agree an auto electrician is the way to go; dealership techs generally just keep swapping things at your expense

jules0621 said:

That's really interesting and perhaps explains why one car but not all go off - if certain cars are more sensitive. Difficult to do something about though, but we'll check out the local area for possible aerials. Thank-you so much.

Also any airports nearby?

marlot

Try closing all the vents, and setting the fan to 'recirculate'.  Just in case it's triggered by some wind coming into the car.

jules0621

Thank-you so much everyone, it is the most frustrating problem. She does live near the hospital with the air ambulance coming and going - would that set it off?? But why one car and not others? No airport otherwise. She has tried the vents - but will suggest setting the fan to re-circulate. And then it'll have to be an auto electrician, although why the dealership don't use them I don't know. Simply handing it back saying we've done all we can is unacceptable in my view when it's still going off at all hours!
Thank-you again - first time I've used these forums for my own issue and it's been really helpful.

BOWFER

jules0621 said:

Thank-you so much everyone, it is the most frustrating problem. She does live near the hospital with the air ambulance coming and going - would that set it off?? But why one car and not others? 

Ah, now there's a distinct possibility - the vibrations from the helicopter.
The alarm switch under her bonnet is perhaps a bit knackered and is 'fluttering' with the vibrations enough to set it off.

Reginald74

Is she too late to reject the car?