Re: Can car alarm be set off by cell phone?

["Sue" <sodom@xxxxxxxxxx>]

My brother-in-law installed his own home alarm system (he's an electrical
engineer), but he didn't use shielded wire, just some stuff he had lying
around.  His alarm would periodically "arm itself" while he was, maybe,
napping in the recliner.  When he got up to go to bed, whammo, the alarm
would go off.  This happened several times, until he finally realized that
it was coincident with his neighbor running his ham radios next door.

Rather than the cell phone sending a frequency the alarm recognizes, could
it just be an electromagnetic field from the phone energizing the car's
wiring?

"mikey" <loismustdie@xxxxxxxxx> wrote in message
news:447b5ab5$0$24246$88260bb3@xxxxxxxxxxxxxxxxxxxx
> And folks walk around with these transmitters nestled up nice and
> close to their brains.
>
> "Jim" <alarminex@xxxxxxx> wrote in message
> news:1148701603.254458.57590@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > DanK wrote:
> > > We have a 2004 Toyota with a factory installed car alarm.  The alarm
> > > goes off randomly.  Sometimes a few times a day, some days not at all.
> > > No physical disturbance is setting it off (it does it even sitting in
> > > our closed garage).  However, we noticed that it seems to happen when
> > > my daughter's cell phone is in the car.  I am still trying to confirm
> > > this relationship (by having the phone in there, or not having it in
> > > there, and seeing when the alarm goes off).
> > >
> > > Could the cell phone be setting off the alarm?  It's nothing obvious,
> > > like the phone being on "vibrate" mode, and receiving a call.  Could
> > > the phone be sending a radio signal that is at a frequency that sets
> > > off the alarm (like the frequency of the emergency button on the key
> > > pad)?
> > >
> > > We had it at the Toyota dealer, but they didn't find anything (this
was
> > > before I made the cellphone connection).
> > >
> > > Thanks for any help!
> > >
> > > DanK
> >
> > Four or five years ago, I had to move a smoke detector out of a
> > business conference room. Every time someone would use a cell phone in
> > the room, it would set off the fire alarm.
> >
> > At my office. When I'm using the office phone (land line) and my office
> > assistants cell phone is going to get a call ( a few seconds before her
> > cell phone rings) I hear strong clicking on the desk handset. Seems
> > like it might be able to cause a problem with a sensitive circuit in a
> > car alarm.
> >
>
>
>
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