# uh oh,



## 96sentra (Apr 9, 2003)

i was installing an amp in my friends car when i think somthin bad happened. i had the negative already hooked up and i was puttin the postive in when some of the positive wire touched a screw on the amp, there was a spark, then the amp smoked. he wasnt there and now i dont think the amp works. my question is, is the amp blown?


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## sr20dem0n (Mar 19, 2003)

hmm...I would say that the amp should be fine but the smoking is kind of suspicious. Did it just give a little smoke where you touched the + wire to or was it actually smoking from the inside of the amp itself?

Have you tried checking the fuses on the amp to see if they're blown? You might have just blown the fuses and it will work fine after replacing them. You should also check the fuse on the + wire near the battery to see if that one is still working. Normally when you short it out like that it will blow the fuse pretty quick


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## 96sentra (Apr 9, 2003)

he is a dumb ass and doesnt have a fuse between battery and amp. i am not sure, but it might have been smoking from the inside, but it wasnt alot. and then after that, i tried pos then neg, but when i touched the neg to its spot, it sparked? i dunno


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## sr20dem0n (Mar 19, 2003)

when you hook up an amp the + and - always spark a bit when you first plug them in, it has to charge the capacitors so it takes a bit of current right at first (hence the spark). That's nothing to worry about, the smoke however could be bad


oh and tell him to quit being a dumbass and get a fuse


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## 96sentra (Apr 9, 2003)

well he owns a honda, that explains the dumb ass part. lol. but, i think it is blown because before when he had it hooked up the power light on the amp was always on. but now, nothing after its all hooked up. i will check fuse though. if fuse is ok, is it blow? p.s. how shitty of pioneer to make a screw right below the hook up spot, that is a very easy mistake to hit.


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## Ninety-Nine SE-L (May 5, 2002)

conclusion, hook the wires to the amp FIRST, then give the wires juice. When you hooked up the amp, the wires shouldn't have been live.


While we're on the subject, how big of a fuse should I use to power a JL 300/4 amp and a JL 500/1?


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## Playa123 (Jul 27, 2003)

> While we're on the subject, how big of a fuse should I use to power a JL 300/4 amp and a JL 500/1?


Well the battery actually powers the amps, not the fuse  =P

Anyway, it should be something that came with the power wire, the 4 ga you talked about in your other post. My 4 gauge comes with a 45 amp fuse i believe.


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## Ninety-Nine SE-L (May 5, 2002)

no, I need to add a fuse myself. So 45amp?


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## Playa123 (Jul 27, 2003)

yup thats what is in my 4 gauge


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## droppinbottom (Jun 30, 2003)

cant just do that (45 amp) dude you need to check and see what size fuse that each amp will require and remember that jl is underrated on their power if it was my set up i would run a minimum of 60amp fuse under the hood or my choice is a fuse breaker under the hood that way if you trip the breaker you can reset it rather than go buy a new fuse $3.00 a fuse can add up over time


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## Playa123 (Jul 27, 2003)

yeah it can, but isn't a 4 gauge wire always going to have a 45 amp?


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## 240sxbegginer (Jun 19, 2003)

my car has 4gauge wire and i run a 60 amp fuse


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## Sethticlees (May 30, 2002)

1997 GA16DE said:


> *While we're on the subject, how big of a fuse should I use to power a JL 300/4 amp and a JL 500/1? *


Fuse your power cable no more than 18inches from the battery.

I looked up the specs on your amps. 
JL 300/4 = 40 amp fuse

JL 500/1 = 50 amp fuse

So about 80-90amp fuse should do it.
Also use a power distribution block to fuse near your amplifiers for each individual power wire.

This Manual.pdf came with my PPI Amplifier. It serves as a great reference tool. I find myself reading it over and over again. The concepts are the same for any amp. So read it well.


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## sr20dem0n (Mar 19, 2003)

Playa123 said:


> *yeah it can, but isn't a 4 gauge wire always going to have a 45 amp? *


no, the size of the wire has nothing to do with the amount of current flowing through it, it just has to do with resistance. You could put 1amp through a 1/0ga wire if you wanted to, or you could run 200amps through it

to answer the question, I say go with an 80


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## Sethticlees (May 30, 2002)

sr20dem0n is right.

Wire gauge has nothing to do with fuse amperage but fuse amperage has a lot to do with wire gauge.

If you system draws 45amps than 10gauge is the smallest recommended wire you should use.
If your system needs 80-90amps than 8gauge is the smallest recommended.

Now distance is the real deciding factor. So check this size chart to be sure. http://paudio.tripod.com/wiregauge.html


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## Ninety-Nine SE-L (May 5, 2002)

ok, one thing I wanted to add, My battery is in the trunk already:
http://1997ga16de.nissanpower.com/cgi-bin/i/images/DSC02964.jpg

I have a wire (soon to be upgraded to 1/0 AWG), going from the trunk to the engine compartment. That line has a 150A fuse. The battery is also grounded 4 times with 4 seperate 4AWG wires going individually from the battery to the chassis. For my Amps, I will be able to run both the grounding wire and the positive wire straight to the battery b/c the battery is so close. Here, I will have a 4AWG (+) wire with an *80amp* fuse and a 4AWG (-) wire BOTH coming from the battery and each going to distribution blocks where the wire splits from 4AWG into two 8AWG wires for each amp.

here's an image:


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## sr20dem0n (Mar 19, 2003)

that sounds good, just make sure your negative cables are short (recommended is about 1 foot long)
if it is going to be 3 feet long then I recommend stepping up a gauge to lower the resistance


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## 96sentra (Apr 9, 2003)

why ground battery?


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## droppinbottom (Jun 30, 2003)

dude if you are gonna do this system dont ground to the battery run your grounds(one from each amp) to a ground block and then run atleast a 4ag line to a ground on the frame


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## Sethticlees (May 30, 2002)

^I think his battery gounding idea is kinda cool!

You could also ground the ground block again. Depending on distance of course, try to stay under 3 feet with the grounds. 

You could also get a fusible power distribution block and place a 40amp and 50amp fuse before each amplifier. This is how the professionals do it.

You’re well on your way to the perfect setup.

Good Luck


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## Ninety-Nine SE-L (May 5, 2002)

not exactly sure what you guys are saying. The battery has (will have) an 1/0AWG wire going from the battery to the engine bay. it also has 4 grounding wires hooked from the battery to the wall of the trunk (paint shaved at the contact points). This is necessary with or without the amp. The reason for so many grounds is so that I have no voltage problems when running my AC or when trying to get spark. I already did most of this right when I moved my battery to the trunk.

As you can see in the link up above my pictured diagram, my battery is in the rear left corner of the trunk. Only a few feet away from where the amps will be. I don't expect either power cord going from the battery to the distribution blocks to be any longer than 5 feet (If I plan to hide the wires). Should I run the negative wire straight to the battery like in the pic or should I ground it to the chassis? I would think that running the negative wire straight to the battery would be a better connection then through the chassis.


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## Ninety-Nine SE-L (May 5, 2002)

BTW, in the pic, the 1/0 wire and the 4 grounds have nothing to do with the Amps at all.


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## sr20dem0n (Mar 19, 2003)

1997 GA16DE said:


> *Should I run the negative wire straight to the battery like in the pic or should I ground it to the chassis? I would think that running the negative wire straight to the battery would be a better connection then through the chassis. *


that's something I'm trying to decide myself, I'm not sure what would be better. I do know that ground wires are supposed to be a foot long or shorter, so if it has to be like 4 feet long to go to the battery terminal it would probably be better to just ground it to the chassis instead.


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## Sethticlees (May 30, 2002)

For large stereo installs (300watt or above) they recommend running a *reference ground* from the amps to the battery ( basically the 4gauge cable from you distribution block to the battery). You moved the battery to the trunk so this should make things real easy. 

If want you can ground the grounding block a second time right to the chassis with another 4gauge cable. Now you’re grounded 4 sure!


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## Ninety-Nine SE-L (May 5, 2002)

well, I assume that 4feet of 4awg wire going straight to the battery would have less resistance than 1foot of 4awg wire, going through a steel chassis to another 1-2 feet of wire and finally to the battery.

I'm just gonna wire it straight to the battery.


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## Sethticlees (May 30, 2002)

Uh... I'm sorry I think I confused you a little! 


Read the WIRE section in this PDF then you should understand. http://www.precisionpower.net/ppipdfs/pcamps/pc42001.pdf



Not to confuse things more but...
The negative (-) terminal on the battery in not absolute ground. The cold hard steel underneath your car is the closest thing you got to absolute ground. 
Still it’s a good idea to ground your battery to the amp distribution block. Read the PDF.


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## Sethticlees (May 30, 2002)

(Taken directly from the PPI .pdf file)
You will need to install an in-line fuse or circuit breaker in the power wire within 18" of the battery. This fuse or circuit breaker is to protect your vehicle from fire in case the power wire shorts to the vehicle body. If you are only using one amplifier, use the fuse rating indicated. If you are using more than one amplifier, add up the fuse ratings for all the amplifiers. This sum is the rating for your main fuse or circuit breaker. 
Use a power distribution block or fuse near your amplifiers
with the appropriate fuse for each individual power wire.

The following is a basic formula to be used as a guide to determine current
NOTE: The ground wire should be the same gauge as the power wire.

Before beginning, disconnect the negative (-) terminal of the
battery prior to working on the positive (+) terminal to prevent
a short to ground. 
Reconnect the negative terminal only after all connections have
been made.


Grounding
Locate an area near the amplifier(s) that is metal and clean an area
about the size of a quarter to bare metal. Inspect the area around
and underneath to be sure you won't drill into wires, brake or fuel lines.
Drill a pilot hole in the middle of this area. Terminate the ground wire
with a ring connector and attach it to the bare metal using a #8 sheet
metal screw and washer or preferably, a bolt, nut and a star washer
(not supplied). We suggest crimping and soldering this connection.
After the connection is complete, coat the area (on both sides) with
silicone or some similar material to prevent rust from developing on
the bare metal.
If your grand total current draw is over 50 amps (or total output
power is over 300 watts), you should run a ground wire beside
your power wire from the battery to the amplifier(s) in addition
to your regular ground wire. Keep the ground and power wires
as close together as possible, and use the same gauge wire for both.
This will ensure that you have a good ground path, and may eliminate
such potential problems as engine noise and overheated amplifiers.
Charging System Considerations
If your grand total current draw is over 100 amps (or total output
power is over 600 watts), you are probably exceeding the capability
of your charging system. Dimming lights and fluctuating voltage are
solid indicators that you need to upgrade your alternator, battery
(or go to multiple batteries), or both.
Keep in mind that your amplifiers simply convert electrical energy
to acoustical energy, and any electrical deficiency will compromise
the performance of your sound system.


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## Ninety-Nine SE-L (May 5, 2002)

well, I think I understand a bit more here. If I ground it straight it the battery, it still has to travel back through the grounds to the alternator. By grounding it to the chassis, the battery and alternator can power the amps equally, correct?


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## SentraStyleEMW (Aug 15, 2002)

1997 GA16DE said:


> *well, I think I understand a bit more here. If I ground it straight it the battery, it still has to travel back through the grounds to the alternator. By grounding it to the chassis, the battery and alternator can power the amps equally, correct? *


The battery really only powers the amps when the car is off. When your car is on and running, it is the alternator that powers everything. Of course your amps will still pull current form the battery when your alternator cannot keep up with the demand of your system.

One another note, a 4 foot piece of 4 gauge to the battery and then to the chasis has more resistance than a 1 foot piece of 4 gauge running straight to the chasis. You'll be better off grounding to the chasis...after all, that's where the battery is grounded to...why waste an extra step going through the battery when it's just going to end up at the chasis anyway?


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## Ninety-Nine SE-L (May 5, 2002)

SentraStyleEMW said:


> *The battery really only powers the amps when the car is off. When your car is on and running, it is the alternator that powers everything. Of course your amps will still pull current form the battery when your alternator cannot keep up with the demand of your system.
> *


well, I know that, my point is, it's just gonna end up going through the battery and then to the chassis.

now tha we got that, where/how should I mount the amps? Can I ground to the seat belt bolt?


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