Firewall Citroen C5

[nonnus]

Hello...
I am in the process of upgrading the sound system of my car (Citroen C5 Mk2 "2004"- Facelift). I've been searching for alternatives for replacing the head unit (Magneti Marelli RT3 Navidrive) even though I could lose the functionalities that shows on the screen, like gps, telematics, climate etc. The only function (info) I was interested in showing on the screen was the "Trip - board computer" function, which also shows the climate control settings. But, I realise that the power of the screen comes from the harness plug connected to the back of the radio.
Then I though, maybe I could power it up using an external 12V source connected to the battery. But then I question myself if I do that, even if the screen is lightened up, will the board-computer(consumption info\climate information) still work? Maybe that info is processed by the head unit. Due to all these doubts I decided to keep the original head unit because I found out that you can keep the stock radio and upgrade your sound system anyway using what is called a (LOC-Line Output Converter) or the more expensive (DSP-Digital Sound Processor) because like this your radio will not "command\send" the "Bad" signal to the new speakers\amp, leaving that process to the Amp. So I'm going this way (at least I keep the originality of the car).

I'm sorry for the long "introduction" but it was needed . So... Because it will be a big upgrade, like new speakers, new amplifier and a new Active SubW "under the seat" option I wish to know is where is it located a firewall to pass through the power cable (8 AWG wire) from the battery\engine bay to the inside of the car...
I saw a firewall at the top right behind the suspension sphere, but for what I see no other cable can pass through that, there is no space, it has a huge harness cables already passing through that firewall.
Is there another firewall, another alternative??
Hope you can help... and sorry for the long text.

[GiveMeABreak]

No not really - you'll have to create one yourself for those cables.

Incidentally the link between the RT3 Head Unit and the Colour screen is fibre optic on these - so be aware - and never remove the screen connection before you have removed the quad lock connector which contains the power lead or it can easily brick the screen and these are rare to get hold of now.

This is the bulkhead crossmember sound deadening on a left hand drive.

[white exec]

...and make sure your new power cable is properly protected with a good rubber grommet/tubing as it passes through the steel bulkhead. Many vehicles have a double bulkhead/firewall, so be prepared for a difficult job. Ensure that the new cable also includes a fuse at the battery end.

[nonnus]

Hello... thank you guys... this helps a lot... knowing this I will be more prepared and try to find a way to do this...

[white exec]

Don't necessarily give up on finding an adequate power source inside the cabin, rather than having to route one from the battery area.

Not sure about the power requirements of your intended audio system, but although it's often fashionable to route welding-size gold plated cables into aidio systems, this is often simply unnecessary overkill - although hugely profitable for outfits that sell the bits. (Don't confuse claimed PMPO wattage of your system with actual electrical (RMS) wattage.)

Quite possible that adequate power already exists in the dash area (eg supply to IGN switch), but you'd need to study the wiring diagrams to establish that. Just need to be careful not to overload an already heavily loaded circuit (eg headlights or blower).