# which is better frame or battery for ground?



## Chyrio

hey guys i have an 89 mr2 and im doing a sub setup. the battery in this car is literally right behind your head so wiring the amp is easy cause the firewall is right behind the subs. the question i have is. in previous car audio setups people ground the amp to the frame of the car. well what i did instead is just run a ground wire straight to the battery. is there any advantage to doing it this way? will the amp get more power or something? o and one of my friends said its better to have a higher gauge ground wire is this true as well? cause i have 8 gauge for + and 10 for - right now


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## jaggerwild

Chyrio said:


> hey guys i have an 89 mr2 and im doing a sub setup. the battery in this car is literally right behind your head so wiring the amp is easy cause the firewall is right behind the subs. the question i have is. in previous car audio setups people ground the amp to the frame of the car. well what i did instead is just run a ground wire straight to the battery. is there any advantage to doing it this way? will the amp get more power or something? o and one of my friends said its better to have a higher gauge ground wire is this true as well? cause i have 8 gauge for + and 10 for - right now


 A good ground is important, the frame is fine witch ever is the shortest(cable). The battery (- negative side) is connected to the frame......... I used to drill a hole, grind it down so the clean metal is exposed then bolt through it, and finally I would paint over it to stop rust as I used to live up north. You can also add a second battery, beef up the alternate and on and on.


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## Chyrio

so grounding to the frame is better?


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## Tomken15

The advantage of connecting the earth to the frame in a neg earth wired vehicle is when the component is some distance from the battery so you don't have to route wires all over the place, but a direct connection to the battery, when practical, is always the best option because of the possibility of corrosion on the frame and don't forget to keep the battery terminals clean & greased.

Is there not a return near where you are taking the feed ?


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## lcurle

when a battery is available, I always choose battery over frame.


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## Chyrio

well the negative wire i ran from the battery terminal to the amp is about 6 feet long. it comes through the firewall, across the firewall in the cab, and down under the passenger seat


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## lcurle

needs to be less than 3' if you can, find a spot to sand to bare metal and secure.


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## jaggerwild

lcurle said:


> needs to be less than 3' if you can, find a spot to sand to bare metal and secure.


 Hey man!:flowers:


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## lcurle

jaggerwild said:


> Hey man!:flowers:


Hey Jagger, got an email the other day that I need to answer a question on here, so I came back and 2 cent everything lol


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## Chyrio

why less than 3?


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## Basementgeek

The longer the run of wire the more resistance you have.

BG


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## jaggerwild

lcurle said:


> Hey Jagger, got an email the other day that I need to answer a question on here, so I came back and 2 cent everything lol


 Yer 2 cents always welcomed!


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## lcurle

Basementgeek said:


> The longer the run of wire the more resistance you have.
> 
> BG


bingo, set a DMM to resistance and check and see what it meters at, with 6' of wire.


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## Chyrio

sorry to sound like a newb: DMM?


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## Tomken15

*D*igital *M*ulti*m*eter

A digital multimeter is best because it's WYSIWYG whereas an Analogue meter parallels 50 Ohms/Volt


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## Basementgeek

WYSIWYG (what you see is what you get)

BG


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## Chyrio

ah ok thank you i will check it


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## jaggerwild

Basementgeek said:


> WYSIWYG (what you see is what you get)
> 
> BG


 I'm still learning after all this time opcorn:


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## Basementgeek

I had to google it as I had no clue either.

BG


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## Tomken15

Thought everyone knew what WYSIWYG meant, perhaps it's just a Brit thing. :smile:

It's txt speak I have to Google :grin:


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## Chyrio

alright so the cable is 5.5 feet in length


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## Tomken15

Years ago when I was trucking, I ran a pos and a neg to and from a battery that was situated on the other side of the vehicle, to power a CB radio and it worked okay.

That was with just standard 12v lighting wire. The reason for using thicker gauge cabling is because it offers less resistance to narrow gauge, but for flexibilty (i.e. routing), you need a multi-core cable rather than single core, which if of the same total diameter, would offer less resistance than the former.

This is why mains cabling is thick single core to accomodate the amperage, otherwise it would get quite warm and could pose a fire risk.

If you have any doubt as to the suitabilty of the cabling you're using, then get advice from your local DIY or an Electrician.


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