Mechanics

ALARM GOING OFF CONSTANTLY.

1997 Renault Megane • 90,000 miles

1997 Megane Coupe. Alarm has recently started started malfunctioning (going on and off constantly). I've had to disconnect the car battery to shut it up.The car has its own factory fitted immobiliser controlled by the key FOB, and I can start and drive the car with the alarm sounding. Locking and unlocking the doors isn't stopping the alarm. The alarm sound itself is different to usual - wobbling pitch bird like noise - sounds like it is broken.I haven't changed the car battery recently which I understand can trigger the alarm. Mine is a very similar problem to this: http://www.2carpros.com/questions/renault-megane-1997-renault-megane-how-can-i-stop-the-alarm-on-a-renault-m--2However, I don't have the alarm control in in glove compartment.Is there a way for me to disable the alarm? Cutting wires or removing it altogether is fine as I don't need an alarm anyway. Thanks very much
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Georgeperkins
March 23, 2012.



Is the alarm factory, dealer installed or after market?

I would suggest checking the alarm control module ground circuit connection.


KHLow2008
Mar 23, 2012.
Thank you, not sure if it was factory or dealer, but I believe it is installed by Renault from new.
It is Renault branded Gold shield II or Silver shield II by Sigma.

Could you suggest where I might find the alarm to check the ground connection as I have now experience with Alarms. Do I need to go in from the bonnet or the dash?
Thanks


Tiny
Georgeperkins
Mar 23, 2012.
Our database does not have any information on this vehicle so I am not able to provide you the location of the control module.

Generally control modules are underdash, it can be at the kick panels or under the center console/dash.


KHLow2008
Mar 23, 2012.
Thanks, I'll try to locate the alarm. If I'm unable to find any obvious connection faults, is it generally safe to cut/disconnect the siren?


Tiny
Georgeperkins
Mar 23, 2012.
That might cause you problrms of battery draining as the alarm is still being triggerred, only the siren is not sounding.


KHLow2008
Mar 23, 2012.
OK I found the alarm mounted next to the car battery. Photo attached. I take it the grey cable bolted onto the metal is the ground you are referring to and should be checked to ensure the connection is good. I'll let you know if that works.


Tiny
Georgeperkins
Mar 23, 2012.
It is sitting next to the battery so chances of wire corrosion etc are high. Check the module to see if there is any ket slot. If there is, you can use the key to disarm it. Seems the module is inclusive of siren.


KHLow2008
Mar 23, 2012.
OK thank you, I'll examine all the connections and check for a key hole. I'll do this tomorrow as its dark now. Thanks again and I'll keep you posted.


Tiny
Georgeperkins
Mar 23, 2012.
Right, it turns out that the box I identified above is just the siren, haven't found the control unit. However I did some research and it turns out that it shouldn't be possible to drive with the alarm active (should be imobilised). This means that in my case the alarm isn't active and the siren is malfunctioning and going off on its own. I opened up the siren and found a 9v backup battery inside. There was a fair bit of corrosion on the battery terminals, so I removed it. I've reassembled the siren and connected the car battery. So far, so goood. Locking and unlocking the doors does sound the usual beeps from the siren. Hopefully the alarm won't sound (I won't be confident until its been quiet for a few weeks.

I'll report back. Thanks for your advice.


Tiny
Georgeperkins
Mar 24, 2012.
You confirmed my suspicions. The backup battery tends to go bad over time and it can also caus battery drain overnight.

Removing the battery should solve the problem of the siren going off on its own.


KHLow2008
Mar 24, 2012.
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