Power shutoff after an hour to rear SAM
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From: Mississauga, ON CA
15 Mercedes C400, 12 Mercedes C250 coupe
Power shutoff after an hour to rear SAM
So i'm hard wiring stuff to the rear SAM, found the "12v" red cable plugged into the SAM which appears to have constant power even when the car is off and locked.
Great I thought, but after about an hour my device no longer has power.
Is there some kind of cut-off or power saving feature on Mercedes cars (specifically an 2008 W204) that cuts power to rear SAM after a period of time? ie. 1 hr
I know I get power for about 1 hour after the doors are closed and locked (confirmed with a LED light tester)
Looking for some insight...
Great I thought, but after about an hour my device no longer has power.
Is there some kind of cut-off or power saving feature on Mercedes cars (specifically an 2008 W204) that cuts power to rear SAM after a period of time? ie. 1 hr
I know I get power for about 1 hour after the doors are closed and locked (confirmed with a LED light tester)
Looking for some insight...
Last edited by angeloxnet; Dec 4, 2012 at 09:51 PM.
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'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
So i'm hard wiring stuff to the rear SAM, found the "12v" red cable plugged into the SAM which appears to have constant power even when the car is off and locked.
Great I thought, but after about an hour my device no longer has power.
Is there some kind of cut-off or power saving feature on Mercedes cars (specifically an 2008 W204) that cuts power to rear SAM after a period of time? ie. 1 hr
I know I get power for about 1 hour after the doors are closed and locked (confirmed with a LED light tester)
Looking for some insight...
Great I thought, but after about an hour my device no longer has power.
Is there some kind of cut-off or power saving feature on Mercedes cars (specifically an 2008 W204) that cuts power to rear SAM after a period of time? ie. 1 hr
I know I get power for about 1 hour after the doors are closed and locked (confirmed with a LED light tester)
Looking for some insight...
There is switched and un-switched 12V in the fuse panel on the right side behind the little door.
Thread Starter
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From: Mississauga, ON CA
15 Mercedes C400, 12 Mercedes C250 coupe
It's the big red cable i tapped into. It plugs directly into the REAR SAM itself.
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'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
Thread Starter
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From: Mississauga, ON CA
15 Mercedes C400, 12 Mercedes C250 coupe
Do you know for certain the big red cable plugged into the top of the rear sam is the "emergency button"? For a flashing LED, it doesn't seem like it would be. Also if you look at the entire sam assembly there is only 1 source coming into the SAM, which is the red cable I mentioned.
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From: SEATTLE WASHINGTON USA
'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
I have tested and tested for several days now, can you gave me an example of what cable you think has constant 12v? That would be helpful
Do you know for certain the big red cable plugged into the top of the rear sam is the "emergency button"? For a flashing LED, it doesn't seem like it would be. Also if you look at the entire sam assembly there is only 1 source coming into the SAM, which is the red cable I mentioned.
Do you know for certain the big red cable plugged into the top of the rear sam is the "emergency button"? For a flashing LED, it doesn't seem like it would be. Also if you look at the entire sam assembly there is only 1 source coming into the SAM, which is the red cable I mentioned.
But I do know about about the fuse panel on the right and have used it for my backup camera power, long ago. The SAM is on the left side and I'd be cautious doing any testing on it because they are expensive.
Just check all the unused fuse holders with the key on and then off.
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From: Mississauga, ON CA
15 Mercedes C400, 12 Mercedes C250 coupe
That green button would have a small 12v wire plus ground. I don't know anything for certain because I haven't looked. I'm just using normal electrical troubleshooting procedure.
But I do know about about the fuse panel on the right and have used it for my backup camera power, long ago. The SAM is on the left side and I'd be cautious doing any testing on it because they are expensive.
Just check all the unused fuse holders with the key on and then off.
But I do know about about the fuse panel on the right and have used it for my backup camera power, long ago. The SAM is on the left side and I'd be cautious doing any testing on it because they are expensive.
Just check all the unused fuse holders with the key on and then off.
I just went into my garage again and the green button is definitely not the same BIG red wire feeding into the SAM.
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From: Australia
C220 CDI SLK 200
Perhaps they remove power to prevent the battery going flat when the car is not used for a long time. The SAM is not the place to connect other pieces of gear to. They are very fragile and will die if not treated carefully. Their funeral is expensive. If you are plugging or unplugging anything into the Sam disconnect the battery first
Last edited by Big Daddy; Dec 5, 2012 at 05:40 PM.
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Thread Starter
MBWorld Fanatic!
Joined: Sep 2007
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From: Mississauga, ON CA
15 Mercedes C400, 12 Mercedes C250 coupe
Here is an update.
I spoke with a Mercedes technician who is a friend, and he confirmed that the rear SAM power is linked to a relay that has a timer, that actually fluctuates based on temperature outside, so it will cut power after 45 minutes to a 1 hr.
I spoke with a Mercedes technician who is a friend, and he confirmed that the rear SAM power is linked to a relay that has a timer, that actually fluctuates based on temperature outside, so it will cut power after 45 minutes to a 1 hr.
That's interesting. Thanks for updating the thread with that. It might help somebody else in the future.
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From: SEATTLE WASHINGTON USA
'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
Did he say what the purpose of this might be?
