# Adding amp - Do I REALLY need to disconnect my negative terminal of my battery?



## jooonnn

Hey there I've been searching the forums a bit for insight on this but I was wondering.

I have already went through a couple battery terminals from disconnecting my negative anytime I do any work on the car. I really think it's because of the heat and humidty we have in south carolina that makes it easier to strip the screws that tighten after market battery terminals rendering the terminal useless. 

Anyways, I was wondering do I really need to disconnect the negative terminal of the battery if the car is OFF and i CAREFULLY connect the positive then negative on an amp I add from a fused distribution block?


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## mattchan2000

If U work on your amp very often, it best to install a power line circuit breaker so that u can deactivate it anytime.


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## jooonnn

mattchan2000 said:


> If U work on your amp very often, it best to install a power line circuit breaker so that u can deactivate it anytime.


Doesn't a circuit breaker only break the circuit between the amps and not the rest of the car?


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## basher8621

I will never work on a car without connecting the negative battery terminal. No matter how careful you say you are going to be you never know what might happen and the end result could cost more than a battery terminal.


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## mattchan2000

Yap...I tot U only need to do the audio equipments....If U need to work on something else..U need to disconnect the negative.


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## Mr. Nice Guy

Anytime you're messing with (removing, or replacing) speaker wires, always make sure your entire sound system is powered off. Any time you mess with the power and ground wires going to any component in your sound system, ALWAYS disconnect the negative battery cable first.


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## Chaos

basher8621 said:


> I will never work on a car without *connecting* the negative battery terminal. No matter how careful you say you are going to be you never know what might happen and the end result could cost more than a battery terminal.


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## basher8621

Chaos said:


>


LOL. That is supposed to say disconnecting. Thats what I get for posting after staying up all night working on the tune.


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## kyheng

Yes and no.....
Yes when you use a small wire to energise HU, amp first or you have the guts to do so... Safety comes last here....
No when you are unsure what you want to do.... Safety first if this is your concern....


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## Aaron'z 2.5RS/WRX

Buy better battery terminals OR stop being an effin Gorilla when you tighten them down.. 

Once something is tight, how far do you continue to tighten it?? 

I mean once the terminal grabs the post, is there any reason to go tighter? 

Are you using the wrong terminal? Pos/Neg are different sizes.. 


Truth is, go ahead and hot swap... It's a gamble... are you willing to up the ante for the gamble??


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## robert_wrath

mattchan2000 said:


> If U work on your amp very often, it best to install a power line circuit breaker so that u can deactivate it anytime.


Absolutely correct. Disabling the In Line Fuse automatically shuts down power going to your Distribution block/power to the amp(s).


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## Mike_Dee

Only if you want to keep your equipment 100% safe, otherwise, you don't.


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## sqshoestring

Not sure what the right way is, but when I mess with power wiring I turn the system on and then pull the amp fuse at the battery. This discharges the caps in the amps so they don't spark on me later, which I've never had damage from but it can surprise you. If you have multiple amps the power can go from one to the other when you hook one up. I leave the negatives hooked up always. When its all hooked back up I put the amp fuse back in and it sparks a little charging the caps in the amps, you could use a test light between it to pre charge instead. They usually tell you to unhook the negative for this reason, they feel that a spark on the negative is safer than on the positive...but my fuse is a foot from the positive terminal anyway. Certainly it is fine to unhook the negative, but then you should unhook the entire car so your HU is also not grounded....I'm guessing that is what they are saying. Taking the negative completely off the battery is the standard way to work on anything on a car but I don't know if you mean everything or just the amp wiring. I don't do it for amp swaps as usually some kind of memory or clock gets reset. (and I am very practiced at doing amp swaps even my wiring is set up to do it)

I always take the positive off an amp first and hook it up last, so the amp is grounded when power is changed, to eliminate the possibility of it wanting to ground on the RCA, though if you pull the main fuse and drained the caps it should not matter. I also unhook the RCA before the negative, and attach only after the amp is again grounded. I see the threat of the amp grounding into the HU as the worst, so I want the amp grounded at all times possible, and for sure grounded when I touch an RCA plug. Far as speaker wires I turn the amps off and do whatever, long as the amp is off it should not matter to speakers or amp.


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## shnitz

Mr. Nice Guy said:


> Anytime you're messing with (removing, or replacing) speaker wires, always make sure your entire sound system is powered off. Any time you mess with the power and ground wires going to any component in your sound system, ALWAYS disconnect the negative battery cable first.


This is the truest statement I've seen in a long time. If you're just switching speakers, then don't worry about undoing the battery terminal. Heck, you can even run the car, but don't have your head unit turned on.

If you're working on an amplifier, you SHOULD disconnect the negative. This is done, because no matter how careful you are, all it takes is a little tap in the wrong spot, and you've fried something.



Aaron'z 2.5RS/WRX said:


> Buy better battery terminals OR stop being an effin Gorilla when you tighten them down..
> 
> Once something is tight, how far do you continue to tighten it??
> 
> I mean once the terminal grabs the post, is there any reason to go tighter?
> 
> Are you using the wrong terminal? Pos/Neg are different sizes..
> 
> 
> Truth is, go ahead and hot swap... It's a gamble... are you willing to up the ante for the gamble??


Aaron has good advice. If you're stripping battery terminals left and right, it's not the heat and humidity. People work in much hotter and much more humid regions than you without breaking stuff on their cars, not that either of those conditions lends itself to making the battery terminals any weaker (besides making you frustrated and short-tempered when you're under your hood). It's your technique. Learn to work on your car correctly, and pulling the battery terminal won't be such an issue.


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## gokiburi

And when you pull the battery terminal, wrap some kind of insulating material around it or cover the post. The cable "memory" can make the cable/terminal want to go back to the post, even when you think you've secured it. Bit me once.


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## minbari

I almost never disconnect it. take the main fuse out and call it good. if there is no 12V on the main power wire you are not gonna fry anything.


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## SpiderX1016

I have done it before when I was too lazy to go snooping for the Radio Code but I try not to.


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## goodstuff

Do you have a pioneer? 
Hot swapping rca's will blow the pico fuse. Don't wanna think about what else could happen.
It's just easier and cheaper to learn the right way then to not disconnect and end up with broken equipment from an unintended short or worse a car fire.
I usually take an empty cardboard duck tape roll thingy and put it around the terminal, so that when the cable tries to bend back to where it was it gets blocked by the cardboard.
I think I have a shot of it somewhere, hold on.

You can sort of see half of it here in the lower right hand corner.


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## gokiburi

^^ Great idea, and simple way to avoid much anguish.


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## goodstuff

gokiburi said:


> ^^ Great idea, and simple way to avoid much anguish.


Thanks. You can't really see the whole thing and this might not work as well on other cars. It pinches between the top of the fender and the fuse box. Some other cars might not have the same setup.


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## SpiderX1016

I just use a rag or something that doesn't conduct electricity and put it in between.


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## TestTones

Many years ago I was installing wire in my car. Using dad the electrician's thick strand housing wire to run head unit direct to battery.

Somewhere in the massive length, the hot lead grounded out, the insulation went up in smoke and suddenly my car is trying to start in gear, lunging slowly forward towards the closed garage door!

Fortunately I jumped out and ran with the wire in my hands for about 30 feet to straighten it out and detach it from the unknown body part it had fused with. Ah to be 17 again!


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## gokiburi

TestTones said:


> Many years ago I was installing wire in my car. Using dad the electrician's thick strand housing wire to run head unit direct to battery.
> 
> Somewhere in the massive length, the hot lead grounded out, the insulation went up in smoke and suddenly my car is trying to start in gear, lunging slowly forward towards the closed garage door!
> 
> Fortunately I jumped out and ran with the wire in my hands for about 30 feet to straighten it out and detach it from the unknown body part it had fused with. Ah to be 17 again!


:laugh::laugh:


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