SL350 2011 WIPER ISSUE

[MBGB]

This is what the Mercedes Trainer told me:
Place a trickle charger on the boot battery, positive on the positive terminal and the Negative to the control box, found by following the chasis earth. This then assists the CAN network to go to sleep, when no use is made of the battery.
Not sure about that but will try anything to resolve this niggly problem. I must admit I also think its the consumer battery issue
Any views?

 

[LostKiwi]

The Malcolm mod is documented somewhere on here.
Another solution to prevent the dreaded lockout is an Anderson connector mounted under the rear of the vehicle. Hook to another battery or charger and it's straight in even if the battery is totally flat.

 

[MBGB]

Is that what you call it Kiwi?

 

[LostKiwi]

Is that what you call it Kiwi?

It's nicknamed after the forum member who documented it and has now sadly passed away.

https://forums.mercedesclub.org.uk/index.php?threads/how-to-fit-a-charging-point-to-a-230.149211/

 

[McDonald]

I've read that locking the car in the garage sets the electrics at rest, not locking it keeps the systems on half alert thus draining the big battery in the boot. I have a trickle charger in the boot and use it when the car remains tucked away for more than a couple of weeks.

 

[MBGB]

McDonald,
Can I ask, have you just done a direct +/- to the rear battery with your trickle charger or did you go to the control box with your negative, which is the advice from Mercedes?
It was they who gave me the advice to leave it unlocked in the garage to save drain!

 

[LostKiwi]

Mine is direct to battery. That's the way Malcolm wired it.

 

[noonboots]

This is what the Mercedes Trainer told me:
Place a trickle charger on the boot battery, positive on the positive terminal and the Negative to the control box, found by following the chasis earth. This then assists the CAN network to go to sleep, when no use is made of the battery.
Not sure about that but will try anything to resolve this niggly problem. I must admit I also think its the consumer battery issue
Any views?

Which control box? I can't think why this method of connection would make a difference.
Incidentally I never see more than 12.8 v on my battery after the charger has cut out. You need a charger specifically for AGM batteries by the way. Ordinary chargers can ruin them by charging with too higher voltage ar ampage.

 

[MBGB]

Noonboots,
Thanks for that. I asked him the very same question. He said it was the best methos as the battery was charged from the front anyway with the front one and the control box negative ensured there was no bi passing going on.
Hopefully, I am doing exactly that................trickle charger straight to the old method of +/- on the rear Merc battery. The one I have in mind has all the safety with it so no need for Malcolms way.
Last idiot question do you guys doing this method, leave your boot lid open or close it, trapping the wire to the charger thus cutting out the boot light???

 

[McDonald]

McDonald,
Can I ask, have you just done a direct +/- to the rear battery with your trickle charger or did you go to the control box with your negative, which is the advice from Mercedes?
It was they who gave me the advice to leave it unlocked in the garage to save drain!

I attach direct on the battery terminals, then close the boot. It all seems to work admirably.

 

[MBGB]

I will try that way, anybody got the part number for the charger who has done this already. If I stick to MB parts it has to be right and hopefully cure the problem, and I'll report back thereafter for those who have this in the future.

Coming back to the loud ticking noise under drivers side dashboard when the wipers won't work and the roll bar light and airbag light flickers, does now sound like a relay. Does anybody know if there is one under there that works from the front to back leisure battery and account for that too?

 

[Uncle Benz]

Have you tried thumping the dashboard next to the ignition key while the fault is occuring? I have changed at least three ignition switches in r230 sl's for the problem you describe.

 

[MBGB]

Thanks for that. I am going to try the trickle charger first and see if that cures the issue. The problem is this is my once in a while car when the sun comes out, and ALL these cars need to be run daily to avoid all these ****** glitches that take years off your life ha ha!! I will report back, but I have a CTEK 12V 5 A charger on order, the same as MB buy and put their sticker on top for three times the amount bought!

 

[LostKiwi]

I connect our charger and shut the boot. Works fine for me.

 

[MBGB]

LostKiwi,
Thanks for that, be good to cure this niggle!!

 

[Viscount]

I've had my 2003 SL350 nearly 3 years and had some niggling electrical issues initially. I had accepted that it would need garaged due water ingress risks and am able to do that and for about 2 years almost always put it in garage and on charge. No issues since. Clearly not an ideal situation as I am asked if it is a PHEV.....

 

[Blobcat]

I've had my 2003 SL350 nearly 3 years and had some niggling electrical issues initially. I had accepted that it would need garaged due water ingress risks and am able to do that and for about 2 years almost always put it in garage and on charge. No issues since. Clearly not an ideal situation as I am asked if it is a PHEV.....

Tell them yes and your environmental credentials will increase. When I had my 911 a neighbour asked the same as I had a charger connected.

 

[MBGB]

Oh well bought the correct lone trickle charger for the boot battery, done two weeks with it, tested it twice, first time thought I had cracked it went like a dream no faults.
Took her out today same fault with battery showing fully charged before I started. Had the radio on and if I persisted to turn the stalk to try the wipers the radio went off and turned back on again, in addition to the flashing airbag light, and the roll bar light on the dash, and the "relay" type ticking sound under the O/S dash.
Plan B when everybody's back at work next week me thinks!!

 

[MBGB]

Why is it these little niggles spoil a ****** good brand. Sometimes think they place too much technology in these cars in the first place. Got rid of the last SL350 2006 because of a sililar fault, but the features I highlight above are new.
Anybody got any ideas on this please, before I go and dig out my Webley with one round in the chamber!!

 

[MBGB]

Uncle Benz,
I went out whilst it was raining and in despair I did thumb the dash as you stated and low and behold it worked. Is it an easy job to change the ignition switch on the 350SL? Thanks for restoring my half smile for now!