Hi - I've had my first Land Rover (110 TD5 1999) for 2 weeks now and love it. Unfortunately the neighbours dont as the alarm has started going off at random, usually in the early hours of the morning.

I've read posts on here and elsewhere that lead me to believe that a door or bonnet switch is at fault. When I set the alarm, the horn sounds twice and the dashboard light is constantly on. This has been the case since I bought the car but only the last 2 days has the alarm started to sound.

When the alarm is sounding, the key fob does nothing. The hazards flash but the alarm continues for about 3 minutes then it silences itself. There appears to be no way other than disconnecting the battery to silence it.

I have disconnected the bonnet switch, front door switch and rear door switch but that has not fixed the problem. The rear passenger door switches have already been removed.

I am booked in at a main dealer for next week but I fear the car may not survive that long!!

I would be grateful for any suggestions.

Hmm. I see no introduction here. There is protocol to follow buddy. You'll probably get a lot more hits if you introduce yourself first...

:yawn:

S

Disconnect ALL door/bonnet switches and tape the connectors up to make sure they can not earth out. Does it still sound the horn on arming? As far as I know only the hazzards should flash two or three times on arming and one long flash on disarming. Horn sounding is to indicate a faulty arming sequence normally because of a mis closed door.

Does the alarm sound if you open the door and get in with all door/bonnet switches disconnected? It should but if it dont try disconnecting the volumetric alarm sensor as this may be at fault.

Have you got a good battery in the alarm fob? They will often set with a low battery but not unset. There is a setting on the ECU to allow "low fob battery" arming which can be disabled with a Nanocom or the like. Its a pain because you can lock and alarm the vehicle but not unlock or disarm until you change the fob battery. I switched mine off so that I can not arm the alarm with a low fob battery. Immobiliser is not affected as it comes on automatically after a set period.

Dont want to alarm you (excuse the pun) but unexplained alarm sounding late at night can often be the pikeys doing it deliberately in the hope that you will get fed up and not set the alarm so you dont wake the neighbours. When you do its when it will go.

Sorry about the lack of introduction, that was rude of me. I have now rectified this.

Thanks for your reply Shifty1962 - I've tested this and the alarm does still sound will all the switches removed, even if I'm in the car. You say 'it should' - why is that? - volumetric sensor?

I will change the battery in the fob tomorrow but it is being recognised as the hazards flash when I 'try' to disarm it, it just has no effect, it insists on running its full course (3 mins approx).

Good tip about the pikeys but I dont think that's it as it has done it at two separate locations.

Welcome mate. Shifty is the DB's and knows his stuff. It's a good place here. You'll learn a lot. I have!

S

flash68 said:

Thanks for your reply Shifty1962 - I've tested this and the alarm does still sound will all the switches removed, even if I'm in the car. You say 'it should' - why is that? - volumetric sensor?

Click to expand...

Yes the alarm should trigger when you open the door with no switches connected because the volumetric sensor will spot you getting in.
If it does not the sensor may be buggered and causing the double horn beep to indicate an incomplete alarm set.

Just thought I'd post to let you know my problem is fixed. Dealer diagnosed it as a faulty bonnet switch. Replaced it and it's been behaving for 2 weeks now. Thanks for the info.

Thanks for posting back. On the grounds that disconnecting the bonnet switch made no difference I am confused as to how fitting a new one has fixed the issue?