Alarm keeps going off

Hello I'm Steve living in Hartlepool North East.
I've owned my disco 2 for coming up 3 years.
The alarm started randomly going off whilst parked on the driveway about 6 weeks ago, had it on diagnostics and it pointed to the ignition switch, got quoted £270.00 to replace!!
As the central locking was also playing up I replaced the drivers door actuator first, it was looking good for 3 days before it went off again.
I purchased a used ignition switch and drivers door handle and fitted them today and it's just went off again this evening.
To save upsetting my neighbours I have disconnected the alarm sounder
and removed fuse for the horns again.
I'd appreciate any helpul advice on tracking down the cause.
regards
Steve

Mine's gone off a couple of time in the last week or so, late at night/early in the morning (of course). I think it's to do with the weather, or more accurately the temperature in the vehicle, which if placed in the sun will be extremely hot, then cooling, giving the sensors the impression there's movement inside.

Not sure that's your problem, but just thought I'd mention it on the off chance.

particularly if you leave any windows cracked open.

Have a go at bypassing the bonnet switch as it can play up and set off alarm .

Thanks for the input guys,
I had previously disconnected the internal movement sensor but it made no difference,
all the door and bonnet switches tested good on the diagnostics, although I will try linking out the bonnet switch for good measure.
As all this started after the massive dowpour we had and water did get in the car,( not from the sunroof I checked my repairs by removing roof lining) possibly from around the windscreen?
I am going to inspect the internal fuse box next as the ignition harness plugs into it and it may have suffered water damage to the connections at the back.

regards
Steve

harrison_steve said:

Thanks for the input guys,
I had previously disconnected the internal movement sensor but it made no difference,
all the door and bonnet switches tested good on the diagnostics, although I will try linking out the bonnet switch for good measure.
As all this started after the massive dowpour we had and water did get in the car,( not from the sunroof I checked my repairs by removing roof lining) possibly from around the windscreen?
I am going to inspect the internal fuse box next as the ignition harness plugs into it and it may have suffered water damage to the connections at the back.

regards
Steve

Click to expand...

how did water get into the vehicle then,rear door seal?????

check for water ingress at the BCU first(behind the glovebox, the one with 4 plugs at the bottom and 1 plug on the side)... this one is managing the alarm/... untill you find the fault you can disable the alarm sounds with tester in BCU-Alarm settings

Most makes of alarm start playing up in hot weather, above advice could work, to be honest I think car alarms are pointless as no one takes any notice of them other than complaining if it keeps going off at night..
Have seen my neighbors strip theirs out completely in frustration both on cars and motorbikes better to just buy a pedal lock for £70

Hello again,

I got a s/hand internal fuse board today,
I disconnected the original and removed the plastic cover to examine the printed
circuit boards, sure enough there was corrosion on two of the bottom plug connectors. It was a releif in a way to see something actually faulty.
I fitted the replacement fuse board which was thankfully in good condition
and reconnected the battery, all looked good until I tried starting the engine,
nothing at all, tried a couple of times and assumed it must be a coded item.
tried again 5 mins later and lo and behold engine started, but I've gained 5,000 miles on the odometer in the process !!!
The original fuse board cleaned up ok and none of the tracks are damaged but I'll keep the replacement in and hopefully this has cured the problem.
If it goes a week without the alarm going off then I'll consider it problem solved.
I may try fitting the original cleaned up fuse board at some future date to see
if it takes off the extra 5,000 miles.
Keep you posted

regards

Steve

Hi,

water was getting in through broken sunroof drains that I repaired and after removing
interior roof are both still OK, maybe there is a leak on windscreen which I'll investigate further.

harrison_steve said:

Hi,

water was getting in through broken sunroof drains that I repaired and after removing
interior roof are both still OK, maybe there is a leak on windscreen which I'll investigate further.

Click to expand...

It may be the roof bars, (if fitted), take the headlining out and drive around for a while to see if the leak becomes apparent ...

Usually around the top of the windscreen ...