Mechanics

- FLAT BAT - ALARM PROBLEM

1999 Mercedes Benz 220cdi

Electrical problem
1999 Mercedes Benz 220cdi 4 cyl Two Wheel Drive Manual 126000 miles

Hi,
My C220 has been flattening batteries with (initially) no obvious reason. I've checked the car for amps drain whilst at rest and found it to be about 330ma which to me seems fine.
Recently I've caught the alarm going off during the night. I suspect that this intermittentally goes off and flattens the battery.
All the door switches seem to be working as does the interior movement sensors. I don't think the mercury switch is to blame as there is no disturbance.
Car usually gets left at about 7pm and the alarm goes off at 2.30am then again at 4.30am.
Problem is intermittent - it can go a week or so with no problems.
Is there any other way the alarm can be triggered, any other ideas?
Many thanks.
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Kodemo
May 7, 2009.




If it has taken you this long to figure out the alarm is going off, obviously the alarm is not doing you any good because you cannot hear it anyway, if you have a fuse for the alarm pull it, if not take it to a shop and have them disarm it.
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Dr Loot
May 10, 2009.
Hi,
Thanks for the response. I've resolved this now. Traced it back to three faults. 1) The electric windows on the drivers side - rear not working and the 'one touch' on the front. Operation was intermittent and has now simply failed completely. 2) The alarm/interior light switch on the tailgate - was sticking. 3) Poorly fitted earth strap.
I think it was because there were multiple faults that it was particularly difficult to predict/recreate and resolve.
FYI, car was stored a good distance from the house it was only when I parked it outside that I noticed the alarm ; )
Many thanks.

Tiny
Kodemo
May 21, 2009.
I am glad you got it fixed, sometimes those kind of electrical problems can be very difficult, especially when you've got the blind leading the blind

Dr Loot
May 21, 2009.

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