Guage Wire???

[mschramek 10+ year member]

Ok Im a little confused and would like some help with determining what guage wire to use for my amps. I currently have two amps- 1 Pioneer Premier PRS-X720 Rated at (1 ch: (4 Ohm) 750Wx1) and 1- Fosgate Power amp rated 50x4 at 4ohms.

The question is I have 4 guage wire running from the battery to the trunk. I will need a distribution block to seperate the wires. Should I get a 4ga to 4ga distribution block or a 4ga to 8ga distribution block.

Also will it be wise to get a distribution block for my ground as well. Or should I just find different ground points. In that case will different ground points create a ground loop.

Thanks for you help..

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[knukonceptz 10+ year member]

You will need to get the total fuse rating or max current draw from each amp. Add those numbers together. That is the systems maximum current draw and you want to fuse the main power wire near that figure. If that number is over 120A and you have a length greater then 17ft, 4 gauge will be to small for that application. Either way you will want a distrbution block. A fused distribution block is normally recommended for the positive side, but not required.

From a distribution block, 8 gauge will handle 80A at 3-4 feet so it can be used. Nothing wrong going larger though. When looking at distribution blocks you wont find many that are 4 gauge in with multiple 4 gauge out. Reason being, how can one 4 gauge supply enough current for two 4 gauge cables if they are at max capacity? (two 4 gauge can handle over 240A total, the single input max is 120A) In most cases you can still use the dual 4 gauge out (again if the output is under 120A), just wanted point out why they are not common

Ground distribution - Makes the install look good, but with two amps is not required if you are going to ground them in the same location and they are close together. If they are on opposite side of the car, it may be better to have a central ground. I usually ground my HU with the amps (I avoid the factory harness) so a ground block is good for multiple grounds.

 

[mschramek 10+ year member]

yea the premier amp has a max draw of 60 amps ....Im not sure of the fosgate amp but it has to be less than that one. Im thinking either 20 or 40amps. Im thinking from the distribution block it wont be more than 3 feet. So the 8 gauge should be more than good for the amps and also the 4ga coming from the battery to the trunk with a running lenth of 30ft.

 

[knukonceptz 10+ year member]

At 24 feet, 4 gauge would support 80-90A MAX. What car/SUV has a 30 foot power wire run?

 

[mschramek 10+ year member]

Im not sure if its 30feet ....I was just taking a rough estimate. But if this helps at all its a 2000 ford mustang. So maybe its a little less than that.

 

[knukonceptz 10+ year member]

The 06 stang has a length of 188" or 15.5ft so its safe to say you'll be covered with 17-20ft max depending how you route the wire. I am sure the two are similiar in length

 

[rocky 59 5,000+ posts]

im going to post jack this a little. im running three amps off of eight gauge to a d-block with a 4 gauge input and the amps are a kx 100.2 a kx 350.2 and a eclipse 400.2. i have around 15 feet of the four gauge to the d-block and the eight is only 3 feet long to each amp. should i upgrade to 0/1 awg and run 4 awg to each amp?

 

[HeatSeeker 10+ year member]

. I usually ground my HU with the amps (I avoid the factory harness) so a ground block is good for multiple grounds.

How do you go about doing this? Do you run the ground cable from the Hu all the way to the back and ground it? Ive heard of some people grounding it directly to the battery's neg. terminal.

 

[knukonceptz 10+ year member]

im going to post jack this a little. im running three amps off of eight gauge to a d-block with a 4 gauge input and the amps are a kx 100.2 a kx 350.2 and a eclipse 400.2. i have around 15 feet of the four gauge to the d-block and the eight is only 3 feet long to each amp. should i upgrade to 0/1 awg and run 4 awg to each amp?

Add up your total fuse ratings, if greater then 120A-130A you would want to upgrade to 2 Gauge or larger. However your amps that power the fronts will not draw much though since they are not playing large bass notes and that causes the greatest demand in the system. I would check what voltage loss you have at the amps compared to the front battery voltage while the system is playing at your normal operating volume.

How do you go about doing this? Do you run the ground cable from the Hu all the way to the back and ground it? Ive heard of some people grounding it directly to the battery's neg. terminal.

Instead of using the wiring harness for power and ground, run 10 or 12 gauge speaker wire from the rear distribution blocks. By connecting all components to the same power/ground sources you eliminate any chance of a ground loop.

 

[HeatSeeker 10+ year member]

Ah ok, Iveh eard of people doing things like that. Ive heard it wasn't good to have your ground too far away from the source though? Or does that just apply to power amplifiers?

 

[knukonceptz 10+ year member]

That is mainly for amps as they draw a lot of current. Your HU will draw only a few amps.