BMW F02 and Car audio.

[FreeZzy]

i want to keep stock HU

the problem is that it will be hard to change a stock wire of battery and alternator, because the battery are in trunk... or maybe i can leave the stock wire of battery and alternator and juste put 0 ga wire from alternator to positiv terminal under the hood and 0 ga from the trunk battery to amplifiers, the hardest is to put the wire from trunk battery to positiv terminal under the hood .

i don't know if you know what i mean ?

Edit: Or maybe i don't need to put a 0 ga wire from trunk battery to positiv terminal under the hood ?

Do you think it's good if i just put a 0 ga from alternator to positiv terminal under the hood

And 0 ga from trunk battery directly to second battery ?

I think i don't need to put a 0 ga wire from trunk battery to Positiv terminal ( of battery ) under the hood ?

Positiv terminal=

Before you pick your wiring, you need to determine what load you're going to be driving.

No need to go full bore with 0ga if you're not intending on using that much power.

BUT, a little extra cable never hurts either

Question #1: How much amplifier power are you intending on running.

Question #2: Question #1 will help determine if you need an HO alternator.

Question #3: After your power needs are determined, we can design the wiring to support the load.

I don't know. i think to buy 2x rockford fosgate t2500 or 1x DC 5.0K, and use my rockford fosgate T600-4

[Wicks]

i want to keep stock HU

the problem is that it will be hard to change a stock wire of battery and alternator, because the battery are in trunk... or maybe i can leave the stock wire of battery and alternator and juste put 0 ga wire from alternator to positiv terminal under the hood and 0 ga from the trunk battery to amplifiers, the hardest is to put the wire from trunk battery to positiv terminal under the hood .

i don't know if you know what i mean ?

Edit: Or maybe i don't need to put a 0 ga wire from trunk battery to positiv terminal under the hood ?

Do you think it's good if i just put a 0 ga from alternator to positiv terminal under the hood

And 0 ga from trunk battery directly to second battery ?

I think i don't need to put a 0 ga wire from trunk battery to Positiv terminal ( of battery ) under the hood ?

Positiv terminal=

Before you pick your wiring, you need to determine what load you're going to be driving.

No need to go full bore with 0ga if you're not intending on using that much power.

BUT, a little extra cable never hurts either

Question #1: How much amplifier power are you intending on running.

Question #2: Question #1 will help determine if you need an HO alternator.

Question #3: After your power needs are determined, we can design the wiring to support the load.

I don't know. i think to buy 2x rockford fosgate t2500 or 1x DC 5.0K, and use my rockford fosgate T600-4

Alright, now we're talkin'

Yep, with those amps you DEFINITELY want an HO alternator with at least a couple big batteries in the trunk.

This setup would be very similar to mine, here's what I did:

-1/0 cable from alternator output to a 300A fuse under the hood. Then run it back to the trunk with another 300A fuse at the trunk battery(s).

-1/0 cable from case of alternator (ground), all the way back to my trunk as a dedicated ground line.

-1/0 cable from the case of alternator to the frame of the car. Plus another 1/0 cable in the trunk bolted to the chassis as a frame ground return.

[FreeZzy]

ok thank you

But, can i do like this ?

- 1 Positiv 1/0 from alternator to positiv terminal (look picture) of battery under the hood

- 1 Negativ 1/0 from altenator to negativ on chassis

- 1 Positiv 1/0 from terminal under the hood with 1 300A fuse to trunk positiv battery in trunk and again with 1 300A fuse

- 1 Negativ 1/0 from battery in trunk to chassis and then connect my second battery directly from my first battery in trunk

( that's what i do on my previous vehicle )

But in my BMW it's hard to put a wire from under the hood to trunk

[Wicks]

Sure, that positive post under the hood would make a great interconnection point.

You could start by only using the chassis as your ground return (no separate negative cable run).

If you had voltage drop issues, then you could always try to add a negative cable later.

If you're only using chassis grounds then make sure the connection area is stripped of all paint and residue and that you bolt into the frame and not just some body sheetmetal.

Personally I'd also fuse the positive cable between the two batteries in the trunk.

Any power source should have its own fuse, just in case that particular source gets shorted and could cause a fire.

Otherwise it sounds good.

[FreeZzy]

Ok thank you for your help

But i don't know if i can put 1/0 wire from front positiv post to positiv battery in trunk.

i'm forced to put a 1/0 wire from front positiv post to positiv trunk battery ? :s

[Wicks]

Ok thank you for your help

But i don't know if i can put 1/0 wire from front positiv post to positiv battery in trunk.

i'm forced to put a 1/0 wire from front positiv post to positiv trunk battery ? :s

No problem, anytime.

Isn't that what you stated above?:

- 1 Positiv 1/0 from terminal under the hood with 1 300A fuse to trunk positiv battery in trunk and again with 1 300A fuse

[FreeZzy]

Yes but i'm not sure i can do that in this vehicle looks complicate. i don't watch where i can put the wire from front to back in trunk

[kirill007]

Yes but i'm not sure i can do that in this vehicle looks complicate. i don't watch where i can put the wire from front to back in trunk

Ce n'est pas possible de router le cable sous la voiture?

Tu as besoin de ce cable, sinon le stock cable va bruler.

I hope you can understand this, my french isn't the best but it should be understandable.

Can't you route the cable below the car? (it will probably be more work but it should be possible)

If you keep the stock cable it will melt, with more then 300A going through it.

[FreeZzy]

You french is not bad i understand you

again thank you for your help but i don't know how to put a wire under the car ? i never do this and i think it's more harder than put wire in the car ..

( i hope my english is not too bad ) ?

Monday I'll see what I'll do

[FreeZzy]

Hello, i see a video on youtube of a fiber optic cable on BMW car.

But here is a problem, I need an optical adapter because the tip does not match with 3sixty optical, look here

Edit: Somebody know where i can find this adapter ?