alarm keeps setting off.. help

[Danny b]

Morning... I am having issues with my alarm, the other night it went off around 2am, this morning at work I parked up walked about 10feet and the alarm was at it again, I checked windows and doors but again it sounded, this when on for 5 times before I just locked it with the key to walk into work.

Does anyone have any ideas or common starting points to solve this?

 

[MODVRS]

I don't use mine any more as the remote packed up, so just use the key. But when I was using it I had two random going off problems; one was the glass-break detector (I think it does that) located in the cubby where the jack lives - it is held on to the panel with a sticky pad but mine had come adrift. The other problem was the bonnet switch had come apart and the guts of it were pushed out instead of the swicth operating.

Probably neither of these is it, but maybe worth a look.

 

[Danny b]

In the past 2 days the bonnet has been up and also been in that Jack compartment so both worth a look. Thanks..

 

[Crispin]

I had two problems on the 120 like that.

The first was tracked down to a faulty door switch. it only set off when it was very cold. A clue was the interior light would turn on and off sometimes while driving over bumps.
I guess the switch was barely making contact and when it was very cold it shrank slightly and caused intermittent faults. It was always coldest at 1-2am

The second was a moth in the car which set of the ultrasonic sensors. Happened 3 evenings in a row.
Can you disable yours? Try disabling them and see if it continues. Look for wildlife in the car

 

[Danny b]

I was cold and damp at 6.30 this morning, also alot of condensation in side. I did notice the interior light come on as instant as alarm triggered?

 

[Crispin]

Open each door at a time, wiggle the switches, see which one triggers the light at a different point to the others.

When "closing" the door - i.e. pushing the switch in with your thumb - the switch should turn the light off quite quickly and then have lots of spare travel. If this is not the case then the switch is suspect.

IIRC the switch was not much from Simon and they all the same so get one, rotate them until the problem goes away

 

[Danny b]

Will go have a look on my break, is there a switch in fuel filler cover? I filled tank on the way in to work this morning..

 

[Crispin]

Not sure on the 90 (or any of them) if there is a switch. Take a look and see. Poke anything that looks like it moves

 

[Danny b]

Not sure on the 90 (or any of them) if there is a switch. Take a look and see. Poke anything that looks like it moves

I have checked all door switches and the bonnet. The fuel flap is just the release pin. All good requiring a very small amount of effort to switch the light off.

 

[Jack VZJ90]

Moisture can also be a problem. If the current from 12 volt slowly drops, it can trigger your alarm.
With mine the power socket from the towing hook, created a small shortcut in milli-amps. Took me a while to find it ....... I disconnected the constant 12+ wire (wich i use for my caravan) by taking out the fuse. Problem was solved. Connector in power socket was a little green corroded.

 

[Shayne]

Simple things first have you tried holding down both buttons on the fob for 30 seconds to reset it .

 

[Danny b]

Simple things first have you tried holding down both buttons on the fob for 30 seconds to reset it .

No.. never knew about that. It's currently set and quiet! Ha ha. I am near Blackpool at a holiday village so won't be popular if it starts going off!!
Never mind.

 

[Danny b]

Ok alarm sounded about midnight then I went out and locked with the key thinking it just Locks it without the alarm? Anyway 8:15am alarm sounded again! I don't think I am popular here! Holiday village near Blackpool..
I checked the sensor near Jack compartment and it was loose with the sticky pad not stuck to anything.. I have unplugged this sensor not and so far it's quiet?

Question for Shayne... to reset with the 2 buttons do I unlock then just press the 2 together or is it a case of press and hold? Will anything sound?

 

[Shayne]

Its in the owners handbook hold both down for 30 seconds to re-synchronize or something like that . I used to have to do it all the time because my central locking would fail rather than alarm issues .

The switch under the bonnet is easily bent down if you lean on it and pulling it up a nudge won't do any harm , just wondering if that could trigger the alarm if the button was only making tenuous contact ?

 

[Danny b]

Hand books in it so will have a read, the bonnet switched checked out good, yesterday I removed it and checked continuity, only takes about 2mm of movement.

 

[Shayne]

Yeah what i mean is the metal bracket the switch bolts to is quite flimsy so if you have leaned on it the switch might only just be touching the bonnet when its closed .

 

[Danny b]

Will check bracket then, from memory it looked fine though. Couldn't find info on alarm reset in handbooks but did tell me it can be set without interior sensors activated by pressing lock twice so going to try that. However since unplugging boot sensor it has remained quiet.

 

[Danny b]

Update as many posts like this end with out conclusion...
Since unplugging the sensor in the boot (Jack compartment) there have been no false alarms. Fingers crossed that has been the cause. Once I back home I shall stick the sensor back in place and plug in again.

 

[MODVRS]

Thanks for the update, nice to see a result. I think the sensor is probably better described as an inertia sensor rather than glass-break as I said before, although it would also pick up a breaking windows. I guess if it is floating around and not attached to bodywork any puff of wind will move it and cause a false alarm. Didn't know you could just unplug it though.