W204 12v Permanent feed

[BenC180CGI]

Hi, I have a W204 and I have a slight issue. I am trying to find a constant 12volt feed for an aftermarket stereo.
I would like to avoid a direct wire from battery.

Can anyone help?

 

[richard]

The main power feed to the radio is constant. If you want ignition then you need to get that from the nearby cigarette lighter
(there are circumstances when that power feed may get interrupted on some Mercedes ...)

Cheers
Richard

 

[Deletedmember130310]

Won’t a constant live feed drain the battery?

Isn’t it safer to wire it through the ignition switch?

 

[GLK]

Won’t a constant live feed drain the battery?

Isn’t it safer to wire it through the ignition switch?

Radio and CDC always have constant power, there's another 'trigger signal' wire, which tells the unit to wake up and to turn off, etc.
That's why you can listen to your music, when ignition is off (but the key is still inserted), and why you can change CDs, when you open the door and glove box cover ...

 

[markjay]

There's a permanent 12v feed inside the OBDII socket under the dash, but from memory the fuse is only 5 Amp or 7 Amp, so this may not be sufficient for a stereo - these would typically use 10 Amp or 15 Amp fuse.

(And it's not a simple case of replacing the fuse, because the wires will be too thin and overheat)

So check the power consumption of the stereo unit first.

 

[BenC180CGI]

The main power feed to the radio is constant. If you want ignition then you need to get that from the nearby cigarette lighter
(there are circumstances when that power feed may get interrupted on some Mercedes ...)

Cheers
Richard

Hi Richard, there is what would appear to be a constant 12v feed but this turns off after a period of time.
Thank you for your input.[emoji1360]


Sent from my iPad using Tapatalk

 

[Deletedmember130310]

Radio and CDC always have constant power, there's another 'trigger signal' wire, which tells the unit to wake up and to turn off, etc.
That's why you can listen to your music, when ignition is off (but the key is still inserted), and why you can change CDs, when you open the door and glove box cover ...

I didnt realise those were constantly live - only when ignition is set to acc. So I've learnt something.

 

[ironpalm]

I had the same issue when fitting an after market stereo, I went to my local indi, they wired to the SAM

 

[BenC180CGI]

[SOLVED] I ended up routing an independent fused feed straight from the battery. There’s a grommet in the bulk head up inside the passenger footwell which leads directly behind the battery. [emoji1360][emoji1360]


Sent from my iPad using Tapatalk

 

[Petrol Pete]

Just out of curiosity why do you need your radio to be live 24/7 ?

 

[BenC180CGI]

Just out of curiosity why do you need your radio to be live 24/7 ?

All aftermarket car stereo’s require a constant 12v along with the ignition 12v.
My stereo would initiate the initial setup every time I turned it on. Once the constant 12v was connected the issue was resolved. [emoji1360]


Sent from my iPad using Tapatalk