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Greg, Technician
Category: Mercedes
Satisfied Customers: 7284
Experience:  Automotive diagnostic tech
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The battery on my Y reg A class was flat when i returned after

Customer Question

The battery on my Y reg A class was flat when i returned after being away for several weeks. When I tried to jump start it using another car , t the moment we fed some power into my car the alarm went off.I tried to charge the battery in the car but the moment the charger was connected the alarm started again. We changed the batteries in th key fob but this didnt help.. Can you advise me ho to disable or stop the alarm/

Bryan Poupard
Submitted: 4 years ago.
Category: Mercedes
Expert:  Greg replied 4 years ago.
Hi Bryan .

You have to remove the battery and recharge it then install and as soon as you connect the battery switch off the alarm with the key fob, or lock and unlock the car with the key in the drivers door then try and start .

Now if the battery is not holding a strong charge then you will not be able to deactivate the alarm system and the problem will not clear .

Still does not work make sure the connections are clean and try another know good battery ,

Do this then get back to me if needed.

My goal is to provide you with excellent service – if you feel you have gotten anything less, please reply back with the reply box below and not the poor or bad service button ,

For further assistance there is no extra charge after accepting.

Rgds Greg
Customer: replied 4 years ago.

The battery is not the problem. We charged it and it will start the engine

but we cant stop the alarm without disconnecting the battery. we changed the batteries in the key fob,would this cause a problem?

Expert:  Greg replied 4 years ago.
Hi Bryan .

Lock the doors with the key ,make sure all doors bonnet and boot are closed first then lock then unlock the door step in and start the car the alarm should turn off.

Is this a aftermarket alarm system or the original .