Alrighty, the car alarm has gone off and woken up all the neighbours for the past two nights.

It'll come on, then stop, then come on again, and stop etc etc.

Does anyone know why this could be?

I've disconnected the battery when I park now, don't see another alternative.

Is there a way to disable the car alarm completely?

Locate the horn for the alarm and disconnect that. First though check the bonnet switch, the car might think that someone has just lifted the bonnet. lol Donno about any switches in the doors that might set it off. Might just work off the switches that turn on the interior light, or boot light, so check those.

Mine went off for no reason when the battery died and voltage went low. Hasn't happened with a new battery. Might be that.

try unplugging the bonnet switch.. i dunno what goes in them but both my tjs had the same prooblem ive just left them unplugged
the only way ive found you can lock it with out turning the alarm on easly enough is open the back drivers door, reach across and lock the drivers door then shut the back door

Is there any easy way to disable the car alarm completely?

Yes, just don't lock your car. lol

Nope, I imagine it is integrated into the electronics of the ECU or BEM, a reflash might be needed. (But that could be wrong)

Actually, I'm looking for a way to set it off deliberately, just to see if it works. Any ideas?

Such a pain in the ass. I live in an apartment block so I can't hear it and the neighbours cop an earful for hours on end.

So there's an independent horn just for the alarm?

Try your bonnet switch first, there is no way to turn it off as such but most of the ones I have had issues with have been the bonnet switch

Such a pain in the ass. I live in an apartment block so I can't hear it and the neighbours cop an earful for hours on end.

So there's an independent horn just for the alarm?

nop just the one horn
another option is pull the drivers trim off and unplug the lock sensor on the key barrel, this will allow you to lock the car with the key with out the alarm turning on
id still try first with the bonnet switch



Actually, I'm looking for a way to set it off deliberately, just to see if it works. Any ideas?
windows down, lock car.. wait for the security light to go off then unlock and open

Alright... so where abouts is the bonet switch plug? I'll have to have a look at it when I get a chance.

you will see near your washer bottle the switch, the plug is under it

nop just the one horn
another option is pull the drivers trim off and unplug the lock sensor on the key barrel, this will allow you to lock the car with the key with out the alarm turning on
id still try first with the bonnet switch.



Of course thats why it sounds so horrible!!! Ive had the same issue, central locking mechanism would just open up for no reason causing alarm to go off, but then the problem just went away after a day. weird..................

Just tested my TJ. Driver's window down, lock, wait for security light to go off, reach in and pop bonnet. Awful horn! At least I know the system works and my bonnet switch works. lol

Must try to see if it works on the boot as well.

Yep. Passenger window down, lock, pop boot, off it goes.

Alright, I tested it out. Bonnet switch untouched, let the alarm get armed, then literally put a fingertip on the bonnet and lifted, and the thing went off.

Disconnected the sensor and tried again with a lot more force, no alarm.

Hope to God that was it, the neighbours are getting PISSED.

That should have fixed it. If your bonnet is aligned and closing correctly probably the switch is faulty. Test it with a multimeter. Does it still have its rubber cap? You could shim it up a bit, so that it opens properly. Or just leave it disconnected. lol

Bonnet switch from wreckers would be an easy part to get, if yours can't be adjusted to make a fix.

I've just opted to have it disconnected all the time. Pretty useless imo, not sure who would go to the trouble of getting an engine crane and cracking open a Magna on the street in the middle of the night to steal it's engine.

Was this an ongoing issue because I have it happening at the moment?

My mechanic fixed this by putting a spacer washer under it.

Common fault. Glad it's sorted. :-)

Just disconnect the sensor. I haven't had it hooked up and it hasn't gone off again since.

Like I said in my last post, no ones gonna force your bonnet open in the middle of the night, get an engine crane and steal anything lol

If you want to re-use the switch at any stage either go and buy another unit, as suggested above, or disassemble the thing, give all the components a good spray with contact cleaner and then reassemble the switch, adding a spacer washer, as suggested by lathiat.