Live feed from battery in C5 X7

ajorge · Post by **ajorge** » 06 Apr 2017, 12:27

Hello,
I'm installing an amplifier (Audison Prima 8.9) in my C5 X7.
I'm trying to get a live feed from the battery to the amp, but I can't find any available spot (grummet) where to run the cable.
Is there a already available place where to run the cable, or do I need open a new one on the firewall?
Best regards,
AJ

Post by **GiveMeABreak** » 06 Apr 2017, 12:43

Your best solution is not to wire directly to the battery, but instead take a power feed from the passenger fuse box via a piggy back fuse.

Have a look at my post regarding dash cams here, the piggy back fuse kit is shown:
viewtopic.php?f=3&t=56750&hilit=Piggy

Xantippa · Post by **Xantippa** » 06 Apr 2017, 16:09

Is it safe to take out 30A from that fuse box? One place to put cable through is that big rubber around steering axle, but I'm not sure if it's suitable for that thick power cable.

Post by **GiveMeABreak** » 06 Apr 2017, 16:25

I've only just had a quick look at the unit (£699 UK retail price - dream on!)
The Cigarette lighter is rated at 30A - and I note that there is no fuse protection provided! But looking at this bit of kit, I'm not sure I would want this sort of power going through the fusebox constantly, so probably best to connect it to the battery directly on second thoughts, but I wouldn't route any wires through the steering axle. Have you checked the routing behind the BSI? If your car is a left hand drive should be behind the cubby hole on the drivers side dash - there's a lot of wiring there that goes into the engine bay.

ajorge · Post by **ajorge** » 06 Apr 2017, 18:14

Hello,
Thanks a lot for your replies.
I really wanted to run the power from the battery instead of getting it from the fuse box as we're talking about 30amps.

GiveMeABreak:
My car is LHD. How do I get from the engine compartment to the bsi? I'm unable to see any holes where cables are being run ...

Best regards,
António Jorge

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Post by **white exec** » 06 Apr 2017, 18:37

Cigarette lighters are normally fused at 30A, with some pretty decent wiring leading to them. If the car has a rear lighter socket, that might be a convenient place to take off from. If you do decide to go for a connection from the main battery junction, then you should use a 30A fuse anyway.

What sort of RMS power if the amp rated at, and what are its supply requirements?

ajorge · Post by **ajorge** » 06 Apr 2017, 18:48

white exec wrote:Cigarette lighters are normally fused at 30A, with some pretty decent wiring leading to them. If the car has a rear lighter socket, that might be a convenient place to take off from. If you do decide to go for a connection from the main battery junction, then you should use a 30A fuse anyway.

What sort of RMS power if the amp rated at, and what are its supply requirements?

I'm planning using an inline fuse in the power line.

The amp is rated at 35wx8 RMS. It is protected by a 30A fuse in the amp and the recommended gauge for power is up to 8 gauge (that's what I'm using)

Best regards,
AJ

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Post by **GiveMeABreak** » 06 Apr 2017, 19:00

Hopefully this will give you an idea of the intermediate harness on your LHD X7.

: LHD Intermediate Harness

ajorge · Post by **ajorge** » 06 Apr 2017, 19:13

I'm planning to attach the amp below the glovebox, so any point on the passenger side would be better than on the drivers side ...

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ajorge · Post by **ajorge** » 06 Apr 2017, 19:15

GiveMeABreak
How does this intermediate harness relate to the front harness?

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ajorge · Post by **ajorge** » 06 Apr 2017, 19:18

There are these two "boxes" (like in pic) that seem to run cables to the cabine (one on each side). Do they conduct cables to the inside of the car?

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Post by **GiveMeABreak** » 06 Apr 2017, 19:58

Can you explain where you have taken this picture as it is hard to determine what it is. I'll have a look later. Also post up your VIN so I am pull the right diagram off.

ajorge · Post by **ajorge** » 06 Apr 2017, 20:48

Sorry

These boxes are under the hood, each at one side at the other most position before the engine compartment ends.
The driver's side one is right after the fuse box, after the battery, and the other one is symmetrically on the other side.
Each one "receives" two big looms of cables and "direct" them to near the windshield wipers motor.

I've sent my VIN in private message.

Thanks a lot for your kind help.
AJ

Post by **GiveMeABreak** » 07 Apr 2017, 01:43

Ok, the picture is upside down, so that confused me - those are the covers that lead to the wiper motors and ECUs (there is one on each motor) as seen at the bottom of the lines indicated at (1):

: X7 Wiper Motor Panels

Unfortunately, there are no pictures of the actual wiring looms. The only thing is the locations of the harnesses:

: X7 Harness Installation

Xantippa · Post by **Xantippa** » 07 Apr 2017, 09:32

Here is one possible place in the right side footwell:

I guess that's the place where steering axle goes in the countries where they drive on the wrong side of the road.

And some say at finnish forum that there's also readymade hole for big cable in the drivers footwell.

French Car Forum