Phantom alarm problems - Again

[Anonymous]

I disconnected the battery to change the starter motor. All seemed ok until a couple of hours later the alarm started going off. I don't use the remote lock as the tilt sensor is faulty (alledgedly) so I reset (key position 2 etc) & locked the car with the key (alarm not set). Barely back in the house & off it goes again with the alarm not set. It was dark by now so I disconnected the battery overnight & left it.

Reconnected the battery, re-set the windows & time (radio stations were still remembered) & took it for a short drive. Locked the car with the key - no alarm. Around 15 minutes later the alarm is going off again. Re-sets don't seem to make any difference so I've had to disconnect the battery to keep it quiet.

How come the alarm is going off when it's not even set?

 

[TheHoff]

Sporadic alarm sirens are often due to a poorly battery, even if it starts ok.

 

[Anonymous]

The battery has the green health circle showing & it checked out ok on my condition tester. Guess it wouldn't do any harm to hook it up for a while.

 

[ronk]

Doesn't the alarm systems have a back up battery fitted to conform with the thatcham status. If that's going west it might cause probs?

 

[Anonymous]

A very good point. The back up battery in my house alarm died so the alarm would go off when the power came back on after a cut.

Putting it on charge now!

 

[Lance]

I had the exact same issue as you describe, mine was the switch under the bonnet. £10 ish from Sopers and 2 mins to change. Alarm has been fine since.

Switch is up by the bulkhead in the middle.

 

[srhutch]

Doesn't the alarm systems have a back up battery fitted to conform with the thatcham status. If that's going west it might cause probs?

Don't think so, if it has mine has expired as I'm guessing most have at 8 years old. Bit like the trackers that no longer work although they keep taking the money :thumbsdown:

 

[ronk]

Doesn't the alarm systems have a back up battery fitted to conform with the thatcham status. If that's going west it might cause probs?

Don't think so, if it has mine has expired as I'm guessing most have at 8 years old. Bit like the trackers that no longer work although they keep taking the money :thumbsdown:

Bandits!

 

[Anonymous]

I had the exact same issue as you describe, mine was the switch under the bonnet. £10 ish from Sopers and 2 mins to change. Alarm has been fine since.

Switch is up by the bulkhead in the middle.

Normally I would agree except the alarm was not armed. I never lock the car with the remote because of the tilt sensor issue.

I did try to run a diagnostic with DIS V57 but it wouldn't auto detect the car, reporting a 'low voltage' issue. Anyway, I put the battery on charge last night & so far there have been no false alarms.

I suspect it may be the original battery in which case it's 11 years old. That's old enough to have issues holding a charge. It's never failed to start the car & it shows the green circle in the check window. My battery condition meter indicated it was ok too but still, an old battery can fail quite suddenly, almost without warning.

Idiot lights are all very well but you cant beat a voltmeter & ammeter on the dash for full time monitoring. Maybe the fad for minimal gauges will pass & we'll go back to an aircraft style bank of gauges like we used to have in the good old days.

BTW - is the boot floor/battery cover supposed to be a cheap bit of hardboard? Very un-BMW like :thumbsdown:

 

[ronk]

Just noticed your location.

Moscow?

 

[TheHoff]

Getting the battery drop tested is the only way to confirm if it's a duffer or not.

 

[ronk]

A very good point. The back up battery in my house alarm died so the alarm would go off when the power came back on after a cut.

Putting it on charge now!

If that (back up) battery starts to loose voltage the drop sensors will pick it up and sound alarm from the main battery.
The house alarm however only sees an open circuit when mains power fails then the battery in the bell box takes over!

 

[Anonymous]

Just noticed your location.

Moscow?

Not quite - I'm about 20 miles north of you! But yes, we're on the same latitude as Moscow.

 

[ronk]

I'm only down south as a missionary!

 

[Anonymous]

Well it's been a few days now & there have been no more problems. Charging the battery over night seems to have done the trick. Just to be sure I got KwikFit to do a battery test - 91% so it's healthy.

Just need to sort out the pdc now. Do the control units need coding to the vehicle?