Car Alarm Issue - Going Off Whilst Driving

[pa402 0]

Hi all

 

Got a strange issue with the car alarm - a toad ai606. It keeps intermittently going off when the car is either parked up & unlocked or whlist driving. When I say intermittently its likes its a dodgy wire or something as it can last half a second or 10 seconds and there doesn't seem to be a way of turning it off apart from disconnecting the battery.

 

I first noticed a problem with the alarm when the siren stopped beeping when I locked/unlocked the car but thought nothing more of it - didn't really bother me that it had stopped working. Thought it might have been something to do with me disconnecting battery when not using the car to save its juice. This then seemed to fix itself and it began beeping as it should.

 

Then the other night the car alarm kept going off as I was driving, rather embarrassingly! I just drove it home and disconnected the battery. Went to look at it today, and gave it a small drive around the block and all seemed fine, was even beeping as it should.

 

Then I was in the process of swapping over the fuel pump relay under the dash and I must have touched something as all of a sudden it went off again. So I disconnected the battery. Reconnected it up and it went off, so started poking the wires under the dash by the fuel pump relay and it stopped, and no longer beeps at me.

 

Could see a black wire joining one of 5 yellow wires that goes into a yellow plug, and also a black wire plugging into the other side of the yellow plug which look like alarm related wires.

 

Sorry for the essay, but question is what do you think could be causing this issue and where shall I look? I'm not very electronically minded! Other option is to just disconnect the siren I guess, I'm not fussed about the alarm as the car has an immoboliser.

 

Cheers

Paul

[Anthony 1,003]

Impossible to say for certain without looking at it really, but this line alone speaks volumes of the quality of the install...

Could see a black wire joining one of 5 yellow wires that goes into a yellow plug, and also a black wire plugging into the other side of the yellow plug which look like alarm related wires.

The yellow plug with yellow wires will be an earth, and it sounds like they've spliced into that to earth the alarm which you shouldn't do.

 

If you say prodding around at the wiring makes the alarm go on and off at random, I would guess that it's the usual shoddy installation with poorly made connections that are making/breaking as you're prodding them and as they move around as you drive.

 

Worth checking that the alarm control module hasn't been fitted underneath the heater matrix and is getting wet because it's started to leak, as that's another that causes no end of issues. It's interesting that unplugging the battery silences the alarm though, as the siren is supposed to be battery-backed so that it will continue working even if you cut the power - I'd guess that's died of old age on yours.

 

When the alarm is going on and off at random, what does the LED on the dash board do?

[pa402 0]

Alarm module appears to be fitted just underneath the ecu and no sign of any water under there.

 

LED doesn't do anything on the dash to suggest alarm is actually going off, nor do the indicators flash so I don't think the alarm thinks its going off!

 

Yeah I agree that seems odd that siren doesn't sound, but alarm was installed in 2000 so I expect the battery is dead.

 

Anyhow, I've unplugged the siren for now and have a fully functioning alarm/immoboliser but just no noise. Will investigate further when I can.