Using negative terminal as ground?

I have recently installed a sound system on my motorcycle. Currently I have power wire on the positive terminal of the battery and ground on the negative. I'm wondering, 1 if using the negative as ground is an ok thing to do, and 2 if that overall setup is good. Note: after thinking about it I've decided to change the wiring to a fuse tap and place the ground somewhere else, but I'm more curious at this point of why, or why not it's a good idea 

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  • 4 weeks ago

    The battery negative IS the ground.  The only reason chassis grounds are functional is because the battery negative is connected to it.  So of course it can be used as the ground for your amp.

    The alternator case (stator on a motorcycle?) is the most "negative" location, but they are generally very electrically noisy so they are not used as an audio ground.  Same with the battery as several non-audio circuits flow through it.  

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    Lv 6
    4 weeks ago

    Having the ground anywhere there is power is definitely not a good way to set it up. That defeats the purpose of having a ground and could cause damage to both the battery, the bike's electrical system (all of it) and the stereo system. 

    The purpose of a ground is so excess current has somewhere to go. It's a safety mechanism. The ground should be places somewhere touching bare metal that has no current at all. That's why putting it on the battery is a bad idea. You want the ground to discharge any excess power the system gets, not give something that already has power more power. 

    That could be a very bad situation (kaboom! possible) having it connected to the battery. 

    The positive power wire should go to the positive or, yes, to the fuse box where there is power when the key is on and doesn't have power when the key is off. It will constantly run and drain the battery if where you tap it in to a fuse slot always has power regardless of where the key is. 

    The negative wire should go to the negative terminal of the battery. Otherwise the system being powered might not have proper power = it won't work right. 

    With a bad ground or the ground connected to the battery (that's a VERY bad ground!) it can not only cause damage to the entire electrical system including the battery but since it's a stereo it will probably always have a horrible noise coming through the speakers. 

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  • Anonymous
    4 weeks ago

    No problem with the negative as ground.  But you need to use a power feed that will have power only when ignition is On.

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  • 4 weeks ago

    maybe you should ask a mechanic to help you with it

    • No need for a mechanic. It is within my abilities to do this. As I said I chose one way and now I am changing it. I understand what I am doing and the right way to do it. It was a question of curiosity.

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  • 4 weeks ago

    Using the negative terminal of the battery is a good idea for a ground. The use of the positive terminal of the battery is not! You need a "switched hot lead" (positive) so you don't run the battery down if you forget to turn the radio off or it develops a short. Use a fuse on the hot lead for sure. Also watch the "speaker ground", a lot of newer radios need the speaker ground run though the sound system (amplifier).

    • Yes definitely. Currently wired to an on off switch, but I want to get rid of that. I wasnt thinking clearly as it was 3 am when I was working on it, but that's why I'm switching to fuse tap so the system will go off with the bike...no speaker ground to worry about with this system (boss MCBK470B)

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