Drain battery issue

[XSalehu]

Hello,

Sorry if I'm not in the right section of the forum.
My father has some battery drain issue since a few months.

He has done some testing but didn't find anything.

He checked with a multimeter and the leak is around 0,25A.

He can't drive really often, so the battery is empty after a few days and he needs a booster.

When he drives frequently, there's no problem.

He checked the fuse, but apparently there's still 0,25A lost even with fuses unplugged.

Alternator has been tested also, apparently no problem.

The only thing weird is the honk that does not work properly but I'm not sure if this can be related.

Thanks for your help, and sorry for my English

Have a nice day,
Léo

 

[Dean Fletcher]

Hi Leo how old is the battery.

 

[XSalehu]

Hello,

I'd have to check with my dad but less than a year, it has already been changed since the problem appears.

I think he tested it and the voltage was fine.

Thanks

EDIT : Confirmed, less than a year ago and a new one 15 days ago

 

[sonic]

Take the fuses out one at a time, see where the drain is going to.

 

[mattkh]

You say the honk does not work. So check the current drain first in that area, There should be a fuse for the horn.

 

[XSalehu]

Hello,

Take the fuses out one at a time, see where the drain is going to.

Yes that's what he did, but didn't see any change on the multimeter, so I assume it may come from somewhere else that the fuse ?

You say the honk does not work. So check the current drain first in that area, There should be a fuse for the horn.

Yes apparently there's a fuse for the horn. We'll check again that fuse tomorrow with another multimeter.

Thanks

 

[sonic]

How are you seeing this drain, are you putting the meter between the battery & one of the terminals.
Are you doing the test with the car locked keys out? That should shut down all the systems.
Not sure if you have Command in the car, that has a habit of not shutting down.

 

[XSalehu]

How are you seeing this drain, are you putting the meter between the battery & one of the terminals.
Are you doing the test with the car locked keys out? That should shut down all the systems.
Not sure if you have Command in the car, that has a habit of not shutting down.

I'm puting my ammeter on my battery, on the "-" and on the wire (sorry I'm not sure how to explain in English, I can take a picture if needed).

Yes the car was locked keys out, and at that moment even when waiting 20-30min I have "0,25A" on my ammeter.

I will try to unplug the command and check if I still have the leak.

 

[sonic]

I think you have it connected correctly, one terminal off the battery then connect the meter to the battery terminal & the connector you have removed from the battery.
Command not shutting down is a known problem which will cause a current drain. I don’t have any experience with Command, but there are others on here who have.

 

[XSalehu]

Hi,

I tried once again every fuse, and I have 0 values for everyone of them...

So it may come from something that is not under a fuse ? Any idea ?

Regrds

 

[ajlsl600]

U say no honk.no horn at any time or when you lock car.?

 

[XSalehu]

U say no honk.no horn at any time or when you lock car.?

Nothing at any time.
We tested the honk on a battery, no sound. And we tried to check the power on the cable and it seems that there is nothing either.

We bought a new honk to test and are waiting to test it... If you have something else we can test, just let me know !

 

[ajlsl600]

I was asking about the alarm siren,horn.do you hear that when you lock the car with key fob .

 

[EmilysDad]

I was asking about the alarm siren,horn.do you hear that when you lock the car with key fob .

Not all Mercs blip the alarm when arming or disarming .... it's in the dash cluster setting on the ML

 

[ajlsl600]

Ok. I was just wonderin? For this op.if alarm siren dont beep when locking maybe he has issue I had.leakin batt in alarm horn shorted .may cause drain .then blow fuse.in my case in boot near batt.? But if its main car horn then no idea .

 

[XSalehu]

Ok. I was just wonderin? For this op.if alarm siren dont beep when locking maybe he has issue I had.leakin batt in alarm horn shorted .may cause drain .then blow fuse.in my case in boot near batt.? But if its main car horn then no idea .

Not it doesn't horn and the alarm does not beep when it is armed (but I'm not sure it ever did).
Can I test what you are talking about in any way ?

 

[ajlsl600]

May be two different things but if you checkk yr hand book fuses ,find the boot fuse for alarm horn siren ,check that.on mine it also stopped rear interior light working ,all resolved for me by disconnecting alarm horn.in my case just behind front p,s bumper in front of wheel I later removed it completely replaced fuse all good,for me.this may be an issue for you or it may be unrelated ?

 

[XSalehu]

Hi,

Horn is working back, I think I misplaced a fuse back when I was doing the test at the beginning .
So I guess it does not come from that, I'll have to test something else

 

[bembo449]

he used a multi meter , not a clamp meter ??

 

[XSalehu]

He has both, I think he used the clamp meter (you are talking about the fuse test right?)