R8 Alarm - causes of sporadic activation?

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GTiJohn
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R8 Alarm - causes of sporadic activation?

#1 Post by GTiJohn » Tue Jul 30, 2019 12:35 pm

Annoyingly my coupe's alarm has started to go off sporadically, including in the night. So far it's happened about 6 times over the last 3 weeks

It doesn't seem to be a local cat, or cat-burglar, as one of the times was when I locked the car using the key, which is something I'd started to do to try and isolate the cause. (The ultrasonic sensor should be disabled if locked on the key.)

All the other times have been after a period of being parked and in weather conditions ranging from sun to rain.

Has anybody had this before and found the route cause?

I'm thinking it may be door switch or lock microswitch related...

I may have to pull the horn fuse when parked if it continues :slapme
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Re: R8 Alarm - causes of sporadic activation?

#2 Post by 1234dist » Tue Jul 30, 2019 1:22 pm

90% door switches, in your case maybe the boot loom again.
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Re: R8 Alarm - causes of sporadic activation?

#3 Post by Cromp85 » Tue Jul 30, 2019 3:04 pm

I have had this same problem quite a few times now. The door/lamp switches have been the cause three times, boot latch switch and the drivers door microswitch.
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Re: R8 Alarm - causes of sporadic activation?

#4 Post by GTiJohn » Tue Jul 30, 2019 5:07 pm

1234dist wrote:
Tue Jul 30, 2019 1:22 pm
90% door switches, in your case maybe the boot loom again.
It has only stated doing it since I 'sorted' the loom :D
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Re: R8 Alarm - causes of sporadic activation?

#5 Post by 1234dist » Tue Jul 30, 2019 8:09 pm

:mouthshut :mouthshut :mouthshut
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Re: R8 Alarm - causes of sporadic activation?

#6 Post by Cromp85 » Tue Jul 30, 2019 9:39 pm

GTiJohn wrote:
Tue Jul 30, 2019 5:07 pm
1234dist wrote:
Tue Jul 30, 2019 1:22 pm
90% door switches, in your case maybe the boot loom again.
It has only stated doing it since I 'sorted' the loom :D
This bit of info might help narrow it down.
Did the broken loom stop your interior boot light from working? I think the switch that activates this light also tells the alarm the boot is open. After unpluging the spade connector from the latch mech, my alarm stopped going off at random. Clean the contacts and squash the spade untill its a snug fit. Grease it up and refit; This fixed mine.
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2002 MG ZR 105 in Solar red (On loan)
1995 214i (On SORN)

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Re: R8 Alarm - causes of sporadic activation?

#7 Post by GTiJohn » Wed Jul 31, 2019 6:49 am

Cromp85 wrote:
Tue Jul 30, 2019 9:39 pm
GTiJohn wrote:
Tue Jul 30, 2019 5:07 pm
1234dist wrote:
Tue Jul 30, 2019 1:22 pm
90% door switches, in your case maybe the boot loom again.
It has only stated doing it since I 'sorted' the loom :D
This bit of info might help narrow it down.
Did the broken loom stop your interior boot light from working? I think the switch that activates this light also tells the alarm the boot is open. After unpluging the spade connector from the latch mech, my alarm stopped going off at random. Clean the contacts and squash the spade untill its a snug fit. Grease it up and refit; This fixed mine.

I don't think my boot light, not the interior light for that matter, has ever worked...

But more digging required :sad

Thank you for the lead :wink3
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Re: R8 Alarm - causes of sporadic activation?

#8 Post by ROVER-25X » Tue Sep 10, 2019 5:26 am

My Cabby does this, no battery fitted at the moment so no problem but it will need sorting, I am thinking it will be my boot loom,
the door switches are easy to clean up, I did a guide ages ago but will dig the photos out.
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Re: R8 Alarm - causes of sporadic activation?

#9 Post by GTiJohn » Tue Sep 17, 2019 4:55 pm

GTiJohn wrote:
Tue Jul 30, 2019 5:07 pm
1234dist wrote:
Tue Jul 30, 2019 1:22 pm
90% door switches, in your case maybe the boot loom again.
It has only stated doing it since I 'sorted' the loom :D
and hasn't done it since I posted this :laughing2
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Re: R8 Alarm - causes of sporadic activation?

#10 Post by The Origina lNom » Wed Sep 18, 2019 2:25 pm

Years ago I had a D16 Cabriolet with volumetric alarm that seemed to be sensitive to some frequencies of Wi-fi.
Drove me nuts trying to find the problem.

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