Battery power to inside cabin of a S3
 

Just got a neat sub-woofer for Christmas and could not hold myself back from installing it. Th PO had already installed a Kenwood (!) head unit and although the sound was OK, it was barely adequate from the 4 (aftermarket) 4" door speakers. It fits easily under the Passenger seat and the hookup was fairly simple once the seat and a few panels were removed. The unit is a Kenwood with a powered amplifier model KSC-SW11 (I really wanted a Cerwin Vega!).
Hooked it all up and fired it up and the sound improvement is simply amazing. I don't need to blow out the windows (or my eardrums), but the quality is fantastic.

One problem - I need to connect the unit to the battery on it's own power supply, but for the life of me, I see no way of running a line from the engine compartment to the cabin. I've pulled back the firewall carpets and the sill coverings but to no avail.

I do not want to hook it into another occupied source (like an existing fuse), so where do I run a line go to get power? The test run was made with the wire running from the open bonnet and open pass. door to the unit.

Looking for guidance!!!

Sometimes you can get a wire or two thru the hole where the LH hood release cable goes thru the firewall

I've found it best to drill a hole in the foot well area near where the cruise control and throttle cables enter the cabin

Cheers
DD

Thanks Doug,
I'll check that hood cable entry position today. The unit has enough wire to reach the LH bulkhead feed post. I will keep you advised.
Ian

if you are going to connect to the firewall Post, why not do it from the inside? It is the same Post, all you need is a Ring Terminal.

Yes, if you can find it ! I've never been able to. Maybe I haven't looked hard enough?

Cheers
DD

For that matter you can tap into any solid brown wire ....as they all are constant battery voltage from the firewall posts in a 'all roads lead to Rome' sense. . Of course you'd need to choose one heavy enough to carry the load of the added equipment.

Cheers
DD

in the driver's side you can see it behind the main harness by removing the dash cap. It is the same as the outside, with a similar rubber boot. The Headlights' switch brown wire connects to it.

I think it would be best to make a new wire with a ring terminal to reach the post tinstead of tapping into the brown wire. Can be run under the floor mats and up the firewall to the Post.

https://cimg6.ibsrv.net/gimg/www.jag...b16e49b958.jpg
Right side firewall Post:

Thanks everyone for your suggestions.
On closer inspection of the area where the Cr.control and throttle cable enter the engine compartment, just inboard of those cables, there are two rubber plugs. I removed one and poked a stiff close hanger thru the interior insulation to see where it came out. It enters the cabin just inboard of the steering column universal joint - perfect. Used a new wire grommet and secured the wire out of harms way.

The next problem was getting from the drivers to the pass. side, but using a thin wooden dowel I fished the wire through just below the radio unit. Trimmed the power wire and reinstalled the panels.

I would seriously recommend this sub-woofer. I can actually hear the music in the car when on the highway, with the volume set to a level where conversation is still easily possible. I mounted the sub itself on 5/8" "stand-offs" to elevate it from direct contact with the carpets and jst behind the raised cross-member beneath the seat. There is about 2 1/2" of clearance between the seat bottom and the unit.

The sub itself (and a nice set of cables) sells for $125 US and a few hours work it's super.

AGREED. I'm using the same unit in my XJ6.

Just for info: to get the right "oompfh" out of a high-end amplifier, the regular wire doesn't suffice.
Running a much thicker positive wire with an inline glass fuse directly from the battery to the amp will give you a lot more stability in the power supply and a lot more guitars & drums from the speakers....
The negative wire should be short, thick and absolutely clean. Best is to make a dedicated ground just for the amp, within perhaps 5 - 10 inches from the amp itself.

Just sayin' ;-)

Have fun!
Pat