Accessory wire to multiple devices

**GeddyT** · 02-17-2005, 01:58 PM

I've searched the forum and couldn't come up with an answer to this question, so I apologize if it's been brought up before, but I've got one last wiring snaffu to figure out with my setup.

I've got an E46 BMW sedan with non h/k stereo system and I installed a car computer in the trunk. The next step is to replace the factory stereo system (or at least everything behind the head unit, which I'm keeping).

I've got two JL amps, one for the sub and one for the speakers.

Now, my question is, I've got a computer and two amps in the trunk and only one accessory wire coming back there. From everything that I've read, it's the white wire going into the factory amp's (soon to be "factory paperweight") harness. I know that accessory wires don't have to carry that much current to get the signalling job done, but I'm now going to be trying to start up three devices from that one wire instead of just one.

So will that one accessory wire carry enough current to signal two amps and a computer?

My guess is that it's not a good idea and that I would need some kind of power distribution block where I can input the car's accessory wire and a 12V lead straight from the battery to boost the current, and output three accessory wires that would carry the proper current.

Does anyone know who makes something like this and where I could get it?

**mindscream** · 02-17-2005, 03:13 PM

Don't fret GeddyT

You can actually wire up several devices to the "remote" wire. Its basically just a signal wire to trip the relay in the amp. Nothing more. If you want to do it nice and neat, yes, use a distro block. But that's all you'll need. You won't need to boost the current any.

In my setup I've got my "remote" or "accessory" wire going to 3 amps, a relay that triggers the power to my car comp, and my lilliput.

I haven't had any problems in the past 8 months I've had it installed.

Hope this helps

**mbuchman** · 02-17-2005, 03:41 PM

Just as long as its 18-20AWG or so, you should be fine. I decided to cheap out on an install I did for my friend, and used the little wire that is in between some RCA wires (this wire was probably 26AWG wire), and about a year later, the wire no longer worked. Do not have any idea what really happened, but I replaced it, and works fine now. That wire was running from the HU to the trunk though.

Being it is a wire that came in the car though, I am sure it will be able to handle the power. You will be fine. Just make sure to run fresh 1/0AWG for the amplifiers. Just need to run the one wire, and could even split it into 3 4AWG wires for the 3 components. Only use a foot or 2 for the 4AWG wire just to be safe, otherwise, you may want to run thicker stuff. Then again, I dont know what size wire those amps want, so may want to read up on them if you havnt.

And if you have never ran wire before from the front of your car to the back(especially 1/0), then leave yourself a day to do it

Hope none of the above is confusing.

Matt

**GeddyT** · 02-17-2005, 06:02 PM

Hey, thanks a lot guys. I guess it'll be easier than I thought. I'll just clean things up with a little distro box, then, and not worry about adding power. Cool.

As far as running 1/0 wire from the front of the car to the back, that's what's great about BMW: battery's in the trunk. No need to run wire.

Well, I guess there's a lot of other things that are great about BMW as well...

**mbuchman** · 02-17-2005, 06:11 PM

Originally Posted by GeddyT

Hey, thanks a lot guys. I guess it'll be easier than I thought. I'll just clean things up with a little distro box, then, and not worry about adding power. Cool.

As far as running 1/0 wire from the front of the car to the back, that's what's great about BMW: battery's in the trunk. No need to run wire.

Well, I guess there's a lot of other things that are great about BMW as well...

Ah, that is nice. Kind of like how the new Cadillacs have the battery under the back seat. Saves a LOT of time!

Matt

**SwapMeet** · 02-18-2005, 05:09 AM

I'm about to put in my amp and sub, and I'm going to need some 12-16 gauge wires to power some other devices. So far I've got 4 gauge wire from the batt. to the distro. block, which then gets split into 3x8 gauge wires. What's the best way to splice the 12 or 16 gauge wires into that set up? Should I splice it into an 8 gauge wire or should I just sneak it into same hole the 8 gauge wire goes into the distro block? Solder the 12 gauge into the 8 gauge and then into the distro block?

**RiXst3r** · 04-13-2005, 09:44 PM

I only get ~9volts out of the little white wire in my trunk... but the same white wire up at the dash gives 12, so I had to run a new wire from the front to the back, cause the opus wouldnt light up without 12v...