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Discussion Starter #1
Hi Y'all!
Concerning my 2005 SLK 350, I have a 94ma parasitic battery draw that is driving me crazy! Pulled all fuses and relays. Draw remains. But...this draw is off and on from 94ma to 12ma and back to 94ma. Now, when I lock the vehicle, all lighting stays off and the drain disappears.
I did notice this morning (in the darkness) that the door surround lights go off and on. Seems to coincide with the parasitic draw. Noticed this with the doors closed and looking down between the door and sill while closed. I believe this may be my draw, but can't figure out why this is doing it.
The door switches are fine and if they were bad, why both doors?
OK, now the question. Does anyone know what causes the door surround light to go off and on about every 10 seconds?
 

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I have no first-hand experience with this... but what exactly are "door surround" lights? You mean the so-called "puddle lamps" that shine on the ground when you open your door?



It is normal to see some draw until you close the car. The car will "go to sleep" once it sees the key out and all hatches closed - including doors, hood, and boot lid.
 

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I notice the same problem -- I'm driving down the road at night and the bottom door light are still on with the doors shut --- and the stay on until 30 seconds to 1 minute after the car is shut off and key is removed. drives me crazy
 

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Didn´t know I had those "puddle lamps", had to check it now. And yes, I have them. And yes they go off instantly when I lock the car. The Swedish summer is not so dark, so you normally don´t see them until now.
 

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The SLK has a number of controllers and computer networks that do not work well when generic electronics are added. If any devices have been added to the car this could cause all kind of weird behavior such as unusual lights and whether the car goes to sleep. That would be the first thing to remove in order to return the car to its normal state.
 

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Discussion Starter #8
2005 SLK350 Parasitic Amp Draw

Thanks to all for your discussion inputs. I had pulled all the fuses and the parasitic draw was still there. As long as the connections are correct, having generic electronics (like a new head unit) should not affect the car's behavior. After all, it's only a radio.
My puddle lamps were pulsating off and on about once every 10 seconds. Locking the car stopped this, but the draw was still present. Right now, there is no parasitic draw and I'm seeing 12ma of draw, which is good. How long this lasts, who knows.
I had disconnected the battery while installing a new radio head unit. Triple checked the connections before re-connecting the battery. Everything functioned great.
I am of the opinion that it may take time for the computer and CAN items to normalize after being disconnected from an electrical source. If the high draw returns, I'm calling a priest for an exorcism as a last resort! :wink:
 

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[As long as the connections are correct, having generic electronics (like a new head unit) should not affect the car's behavior. After all, it's only a radio.
[/QUOTE]
In this case, it's not the radio, but all the other factory components looking for the factory radio, that you'd need to address. What did you replace, and with what?
 

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I have to ask, why are you chasing a draw that small? Anything 50 mili-amps and under acceptable in any car.
Remember your anti-theft system is always on and though it draws very little, it still draws some.
That is why if you leave the car sit for an extended period of time the battery will be dead and you can't shut it off without pulling the fuse.
There are many ways to locate a parasitic draw the most common is to disconnect the negative terminal, connect a muliti-meter with amp capability (Some don't have it, mostly the cheap ones) one lead to the bat post one lead to the bat cable. It will read in amps, so if you have less than 50 mili-amp draw it may or may not read it if nothing is showing then leave it alone, there is no problem.

If you insist on chasing Mili-amp draws, you have to use the "Better Way" for modern cars. rather than explain it here is a link to a Youtube video by a guy who seems to understand his electrical ****. Better than most car mechanics who may know the **** but they don't really understand the details.
If the link doesn't work, look up HumbleMechanic on youtube.

 

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Hi Y'all!

Concerning my 2005 SLK 350, I have a 94ma parasitic battery draw that is driving me crazy! Pulled all fuses and relays. Draw remains. But...this draw is off and on from 94ma to 12ma and back to 94ma. Now, when I lock the vehicle, all lighting stays off and the drain disappears.

I did notice this morning (in the darkness) that the door surround lights go off and on. Seems to coincide with the parasitic draw. Noticed this with the doors closed and looking down between the door and sill while closed. I believe this may be my draw, but can't figure out why this is doing it.

The door switches are fine and if they were bad, why both doors?

OK, now the question. Does anyone know what causes the door surround light to go off and on about every 10 seconds?


as far as i know sir in the front sam exist an pcb its responsible for auto light and split dc voltage to all system even if the car are off
so remove it and with view test for any capacitor and moisture and try to clean ,,,
only for precaution


Sent from my iPhone using Tapatalk
 

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Discussion Starter #12
Solved parasitic draw!

Finally found the ghost in the machine! This parasitic draw only happened after I installed a new head unit. What fooled me is that I pulled it's fuses and even physically disconnected the unit, yet the amperage draw remained. So, nothing to do with the new head unit installation. Wrong!
Found a very discreet remark on a forum about the steering wheel control module someone installed with their new head unit. He stated his steering wheel controls for the new head unit did not work and the SWC modules he added were also causing a battery drain. My SWC did not function as well.
I opened up my SLK's center console, unplugged and removed the SWC modules. No more drain on my battery! These modules are connected via hard wiring and removing the head unit or pulling it's fuses had no bearing on their communication with the CAN bus. The constant communication queries with the CAN bus is what caused the parasitic drain. My SLK has been sitting for several days now with no amp drain.
Thanks to all who responded. I appreciate the input.
 

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I think that was me ...


I ended up with a 2 pole relay, powered from the switched live - it disconnects the SWC CAN lines when the car is turned off


Again - as per the OP's posts, it took a while to find!
 

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Discussion Starter #14
No, it was not you, but I wish you had brought your experience up many days ago. Would have saved me a lot of trouble.
 

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I have to ask, why are you chasing a draw that small? Anything 50 mili-amps and under acceptable in any car.
Remember your anti-theft system is always on and though it draws very little, it still draws some.
That is why if you leave the car sit for an extended period of time the battery will be dead and you can't shut it off without pulling the fuse.
There are many ways to locate a parasitic draw the most common is to disconnect the negative terminal, connect a muliti-meter with amp capability (Some don't have it, mostly the cheap ones) one lead to the bat post one lead to the bat cable. It will read in amps, so if you have less than 50 mili-amp draw it may or may not read it if nothing is showing then leave it alone, there is no problem.

If you insist on chasing Mili-amp draws, you have to use the "Better Way" for modern cars. rather than explain it here is a link to a Youtube video by a guy who seems to understand his electrical ****. Better than most car mechanics who may know the **** but they don't really understand the details.
If the link doesn't work, look up HumbleMechanic on youtube.

https://www.youtube.com/watch?v=lRcj1fQcWwU



Good video that IMHO, unfortunately looks like I need to be doing a bit of this on my car hopefully this will put me right.
 
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