Installing power cable for amp through bulkhead/firewall

[daimo_45]

Hi guys I'm new to the forum and would like to call up on some help. I want to put my amp and sub into my car and was wondering:

1 Do I have to take my feed from the battery within the engine bay or is there another 12v source in the car?

2 If so, where do you pass the live wire through the bulkhead/firewall (is there already a grommet?

3 Can I take a phono (RCA) feed from the oem head unit?

4 Can I take a remote feed from the oem head unit?

5 Where will be the best place to earth the amplifier?

Right-hand drive UK 330d touring 01/02.

Any help would be appreciated.

[NEOslim22]

first off, your battery is in the trunk.
not to sure about the rca from headunit, i am sure some type of adapter is made. You can run a remote from the oem head unit. There are tons of places to ground it in the trunk, i used the battery.

[BmwAudio32]

1. No, in fact the battery is in the trunk under the passenger side black plastic tray, so wiring amps is really easy.

2. Answered by first quesiton, no need to go into the engine bay..its all done in the trunk.

3. Not from the headunit itself directly, but using a LOC such as the Soundgate lc6 you can get yourself an RCA signal. This again can all be done in the trunk as thier is a factory amp in the left side of the trunk, and all wires from the headunit come there. Again this only applies if you don't have the Eurospec "base system", which was the only e46 setup without a factory amp. In this case a normal LOC will have to be used at the headunit at it would be putting out speaker level signals right from the head.

4. Yes, there is a remote wire from the OEM head that terminates at the OEM amp in the trunk. You can tap this and have a remote signal for other amps.

5. Grounding point depends on where you mount your amp. But if you mount it near the side of the trunk where the OEM amp is, there is a grounding block back there that BMW used for all audio components, and you can attach your ground there.

[daimo_45]

Thanks, that is very helpful. Don't think I have the amp.

[daimo_45]

I don't have an amp so will I need to purchase a LOC like this for example: http://www.limitedgoods.com/itemView.php?ProdID=63719&source=FroogleUK&medium=free&campaign=FroogleUK
Could I not take a feed from the back speakers?
What colour is the remote wire in the harness and will I have one as I do'nt have amp?

[BmwAudio32]

In your case, yes you can take the feed from the back speakers. In american spec cars they all have an amplifier, so the signal at the speakers has always been crossed over, but in this case I think its just sending a normal full range signal, maybe has passive caps on it so check to see. But that should work fine. Now i'm thinking there is not a remote wire on that car since it doesn't have an external amp, but you could either run a wire all the way from the headunit and hook it to the headunit's switched power wire, or get one of those remote relay boxes that comes on and off with a signal. Now as for whether you have an amp, how many speakers does your car have? If you have a 3 way front setup you probably do have the amp.

[daimo_45]

Pretty sure I don't have the amp. Where would it be? I have 2 mids and pillar mounted tweets in front, 2 in the rear (coaxial I guess) and a further 2 in the boot (trunk). CD changer is on the left side and cannot see amp nor on the battery side.

[BmwAudio32]

The would be on the cd changer side, behind the carpet. But It sounds like you do have the eurospec one with no amp.