S 350 2004 petrol Battery flat after a few days

[tich]

Car won’t even open with remote control and battery flat after leaving not using it for a 5 days!
Mechanic checked battery and said it was charging ok.
Replaced new battery ok for a few days then same issues!
It’s obviously a drain whilst parked any one have had similar issues?
Thanks

 

[EmilysDad]

Car won’t even open with remote control and battery flat after leaving not using it for a 5 days!
Mechanic checked battery and said it was charging ok.
Replaced new battery ok for a few days then same issues!
It’s obviously a drain whilst parked any one have had similar issues?
Thanks

That says the alternator is OK but that doesn't mean the battery is not fubar'd

 

[tich]

Yes I understand but I’ve replaced it with a brand new battery!
It worked fine until I parked it for 4 days and back to not even opening the car or starting?

 

[EmilysDad]

Yes I understand but I’ve replaced it with a brand new battery!
It worked fine until I parked it for 4 days and back to not even opening the car or starting?

Oops! Sorry ... I missed that bit

 

[tich]

No worries at all the reply is appreciated!

 

[Blobcat]

There are any number of devices that can stay active instead of shutting down. Comand is one of the favourites for not switching off and draining the battery - any wet footwells or boot?

 

[tich]

I’ll check those areas once home and update !
Thanks

 

[tich]

No Wet/Damp areas at all!

 

[kid-jensen]

Good chance that Comand or the alarm is causing the drain.

Disconnect those, and if it's still draining, use the 1/2-Split method (pull half of the fuses, then halve again, etc, etc.) to find the problem quickest...

 

[tich]

Thanks will try and report back

 

[tich]

I’d be delighted if any members are able to sort this out for me!
I’m not inclined to take it to those Rip off main dealers.
Thanks

 

[Wighty]

I’d be delighted if any members are able to sort this out for me!
I’m not inclined to take it to those Rip off main dealers.
Thanks

What about an Indy ?

 

[Oldspanners]

I’d be delighted if any members are able to sort this out for me!
I’m not inclined to take it to those Rip off main dealers.
Thanks

If you want to trace the problem yourself follow this youtube video. A comprehensive way using only a simple multi-meter. P.S. Make sure your car is "asleep" first as shown.

 

[McDonald]

Tich, if you say where you live someone will be able to recommend a good indy.

 

[peter129]

Hello, I'm new to the forum but I had a similar problem with my clk270cdi last year.Battery started going flat after about 2 weeks, thought it wanted replacing so spent 100 quid on a new Bosch battery and 2 weeks later that was flat. checked everything could think of that would drain battery but found nothing then a neighbour told me about his mother-in-laws merc (same model). Apparently there is a heater in the block that is connected directly to the battery and if the thermostat fails it drains the battery over a short period of time, I know yours isn't the same engine and a diesel but might have the same system. Had to cut the wire at the heater in the block and bingo no problem since.Please ignore if I'm talking rubbish.
Peter.

 

[mattkh]

Heated seats in this case is my penny worth.

 

[Rappey69]

use the 1/2-Split method (pull half of the fuses, then halve again, etc, etc.) to find the problem quickest...

Why this method over pulling each fuse one by one? Im just curious as I have a 0.14A parasitic drain so pulled each fuse then replaced but still have the drain.
Car is ok if used regularly but dies in a week..
I presume heated seats, command and alarm go through the fuses? If so then I can eliminate them.

 

[Blobcat]

Why this method over pulling each fuse one by one? Im just curious as I have a 0.14A parasitic drain so pulled each fuse then replaced but still have the drain.
Car is ok if used regularly but dies in a week..
I presume heated seats, command and alarm go through the fuses? If so then I can eliminate them.

1/2 split method is a quick way to narrow down electronic faults.

 

[Flyinspanner]

... and remember you may have more than one fusebox.

 

[Rappey69]

Ive done all the fuseboxes but meter still showed a drain
Alternator or starter motor are two things ive not checked yet as that means crawling on my back under the car on the driveway..
Any other electrical items that are not ran through the fuse box ?