W213 hybrid. Fuse 313 for cigarette lighter doesn't disconnect power?

[Shep645]

Hi, I have a 2021 E300de hybrid (W213 I think) and wa t to hard wire a nextbase dashcam with a nextbase hard wire kit.
The fuse allocation sheet says fuse 313 in the front passenger footwear is for the front 12v socket.
When I plug a USB adapter with LED indicator light into the socket, the LED lights when the ignition is on and as expected, goes out when the ignition is switched off.
However, if I pull fuse 313, the LED remains on when the ignition is on, which seems to suggest that this fuse isn't for the 12v socket.
I've tried pulling all the other fuses in this box one at a time and the LED remains on.
Is thd socket controlled by 2 fuses as the fuse sheet also lists #457?

Thanks!

I've added photos of the fuse allocation sheet, fuse box and VIN plate.

 

[Diesel Benz]

The fuse chart in the car is always confusing. It names fuses that affect the operation of a particular component or function. The 12 V power socket fuses are 456 for the trunk, 457 for the front socket, 458 for the rear centre console socket.

Note that it may take some time before these switch off, the same with USB connectors.

 

[Shep645]

The fuse chart in the car is always confusing. It names fuses that affect the operation of a particular component or function. The 12 V power socket fuses are 456 for the trunk, 457 for the front socket, 458 for the rear centre console socket.

Note that it may take some time before these switch off, the same with USB connectors.

Thank you.
The led on the USB adapter goes off as soon as the ignition is turned off.
I also checked the socket for fuse 313 with a volt meter and it is always on.

So why is fuse 313 listed as front 12v socket? If not for this, what does it do?

 

[Ted]

You could try it with a testlight rather than a dvm.
Sometimes the high impedence of a dvm will show a voltage when there isn’t enough current to drive a load.
Just a thought.

 

[Diesel Benz]

Thank you.
The led on the USB adapter goes off as soon as the ignition is turned off.
I also checked the socket for fuse 313 with a volt meter and it is always on.

So why is fuse 313 listed as front 12v socket? If not for this, what does it do?

F313 is for the multimedia control unit (I read all this from a 2020 diagram, theoretically they may have changed the fuse allocations for a 2021 but it usually does not happen). The multimedia control unit feeds power to the USB sockets. I do not see the connection with the 12 V power socket, perhaps there is.

Someone posted on another forum that the front and rear USB-connectors switched off but for some reason took more time for the other. Wife has a 2021 E-class, could go and check from that car but wouldn't want to walk all the way to the garage (15 metres).