matk

Further to my last query re a current drain, the car alarm is going off when the consumer battery goes too low.

This is despite me leaving the car unlocked.

I don’t have the time to deal with this immediately, so I’m considering just disconnecting the Consumer Battery until I’m able to investigate further.

Im aware that afterwards I’ll have to reset ESP, windows etc, but are there any other downsides? And reason why it would be dangerous to do this?

Gene Fiorot

Does the Alarm horn have a separate fuse? If so pull it until you replace that horn.

matk

I’m not sure if the alarm has a fuse. Anybody help?

sivikvtec

Yes, it’s in the underhood fuse box on the drivers side. 7.5a from what I remember.

MikeJ65

Should be F25.

Frederick NL

The 7,5 that's 3 third in the row

Tom Manning

You can disconnect the rear battery safely for as long as you like. That's what I do after every drive.

As the batteries in the alarm siren module age and leak, they cause the thing to go off on its own, or to short out and blow the fuse anyway. Many here just pull the fuse and forget the alarm.

cdk4219

On most of my Mercedes cars, the alarm fuse is linked to the antenna amplifier as well as the remote entry. When the fuse is pulled or blows due to the alarm siren short circuit, neither the remote entry or antenna signal for the radio work well at all. Is this the same for the r230? What does the BCM decide to do if there is a parasitic draw but only the convenience battery is disconnected?

Frederick NL

F25 secures the alarm horn and nothing else.