Grounding Options, Build Advise

[acidikbass20]

Alright, so I am throwing back and forth the idea of the build on my Malibu. It's a daily rider that will compete in SSNW. I am throwing back some ideas and have heard from each side, but I can get a larger group of ideas online then I can talking to individual people. This would be a place for some useful information to others as well. There are my 2 areas of thought. I am doing 2 runs of 4/0 wire, and have these 2 possibilities. Will be running a Sundown SAZ-4500 on a single 15", 2 d3100s in the rear, with a DC270xp alternator up front.

1. Run one wire hot (positive) and one ground (negative). I always thought that this would be the proper way to go. Make a complete circuit (modern theory of current flow) of alternator to front battery, through wire to back battery, into the amplifier, into the subwoofer, back to the amplifier, back to the back battery, through the wire to the front battery, and to ground. I never really thought of option 2 seriously until it was brought to my attention today.

2. Run both wires hot (positive) and ground (negative) one in the front and one in the back, using the cars frame to proved a closed circuit. This makes more current flow possible, and does not use the wire as a source of power if the car is off. This provides more power when the car is on and the alternator is running, but less when it is off. Since I would be competing with the car on and obviously driving with it on, this is now also an option.

For everyone popping in an opinion, thank you for the advise and experience. Please provide explanation behind your opinion, that's where my decision is based. Thanks guys. I will throw up a poll here too.

-Steve

Edited February 27, 2011 by acidikbass20

[acidikbass20]

What was the question?

Either 1 or 2.

[Autruche]

run one + and one - straight from up front. Frames are not as good of a ground as a direct run to the front battery or alternator.

[sprkn_ranger]

Yea the absolute best ground is the -(negative) terminal on the battery itself. The next best I would think is a good chassis ground.

[acidikbass20]

Thanks for all the input so far, anyone else?

[Purplehaze]

Man, I am no professional, and I could be wrong. But I would think it would be better to use the chassis ground, and use your wire to connect it in multiple points. That way the car's metal and the wire both work together for the entire electrical system. I just came across this same issue, and I chose not to ground directly to the battery alone, but both directly and indirectly, if that makes any sence.

But again, I'm no pro. But my dad is a 40+ year industrial electrician, and his opinion was that I did it right. But he will also tell you he is industrial, not automotive electrician. So who knows. But you can see how I did it in the link in my sig. Let me know what you decide, and what you think of mine.

[n8ball2013]

I have an 09 malibu and I did one + and - all the way from the front to the back. I didnt want to put any holes in the back of the car. You wont be fitting a 15 either without firing up.

[uhoh_45]

you could do 2 runs 4/0 posative and run a smaller ground up front as well as framing to chassis

[dangerick18]

Man, I am no professional, and I could be wrong. But I would think it would be better to use the chassis ground, and use your wire to connect it in multiple points. That way the car's metal and the wire both work together for the entire electrical system. I just came across this same issue, and I chose not to ground directly to the battery alone, but both directly and indirectly, if that makes any sence.

But again, I'm no pro. But my dad is a 40+ year industrial electrician, and his opinion was that I did it right. But he will also tell you he is industrial, not automotive electrician. So who knows. But you can see how I did it in the link in my sig. Let me know what you decide, and what you think of mine.

are you sure that won't create ground loops?

[SPLadd1ct]

A sundown 4500D going to a single 15" driver, hm that sounds strangely familiar? Also two D3100's in the back, that's also really familiar. You should check out my build log in my signature acid.

I am just going to do 4 runs of Stinger HPM 1/0 AWG wire from the front battery to the back battery (2+ and 2-).

What subwoofer are you gonna have powered by the Sundown 4500D?