I do believe that is about as stupid as saying your cables sound better because the electrons are aligned. So do you run your home system off of a Honda generator because it 'has power in it' instead of relying on the power companys mile after mile of line?(chassis) More seriously though, NEVER EVER run anything to the negative battery post except the main battery cable.

Here is why: When we install stereos and accessories and everything goes well it probably doesn't matter. The trouble you get into is when something else in the electrical system goes wrong. If the negative lead of the amp runs all the way to the battery post and if, for whatever reason, the ground end of the negative battery cable comes loose or the cable develops a poor connection between the cable itself and the end, guess what is going to be holding up ALL of the ground current for the vehicle? It will be the amp. (This can happen if the amp is grounded to metal. That happened at the USACi last year, on a non driven vehicle.) And from there, it may work its way back through the RCA cables to the head unit. And from the head unit to wherever IT is grounded, assuming it is not also grounded directly to the battery. I have had people tell me that their fuel guage was not working correctly because of a poor ground on the tank. Guess what they did? They ran a wire all of the way from the sending unit on the tank to the negative post of the battery. Again, the possibility exists for that little wire going to the gas tank to hold up the ground current for the entire vehicle. I wonder how hot things could get on the gas tank when this little wire tries to pass starter current?

Another thing concerning hooking the negative lead from the amp directly to the negative battery post: When the car is running with the system quiet, current will be flowing into the + battery post (conventional flow) from the alternator and out the negative battery post into the engine block for charging the battery. That is a relatively small amount of current compared to what is going to be flowing when the amp is cranking out the power. When the amp is cranking, current will flow into the negative lead from the amp and onto the battery post/connector and NOT INTO THE BATTERY, but back through the battery cable into the alternator since the alternator is what is supplying the current when the car is running. So not only do you have the additional loss of the lead from the amp you have the loss of the battery cable also.

If anyone doubts my post, I would like to have you unhook the far end (non-battery) of the negative cable and leave the amp hooked to the battery. Try starting your car. Let me know how much the damage is...

Lets say you have twenty feet of 8 gauge wire and your amplifier suddenly needs 100 amps. Voltage drop is equal to the current (100 amps) times the resistance. Using a power wire resistance table we can see that 8 gauge wire has a resistance of 0.000739(approx.) ohms per foot. Multiply that by the twenty foot length of wire we have to get a total resistance of .01478 ohms. That doesn't seem like much but relative to the voltage of a vehicle's electrical system it is.

E = I x R or voltage = current multiplied by resistance
E = 100 amps x .01478 ohms
E = 1.478 volts is the drop you will see from the battery to the amplifier.

Now add another twenty feet for the ground, its not practical in his case.


The chassis will be more than sufficient in this case.

 

Tickle Fight!

But seriously, Diesel is has the best advice on this one...

 

Just when I was starting to think 12v DC systems were pretty simple Haha.

 

they are until you start adding high-amp accessories

 

Yeah I have too many toys hooked up. Hopefully that gc alt will solve some issues..

 

ROFL.
Cliff notes.
Diesel says don't do the "big three."
Diesel says you can fry the amp grounding to neg terminal.
Diesel has never installed an alternator.



Yeah, I agree with part two. If you don't update your ground AND the negative falls off AND the amp is screwed into metal AND you try to start the car/truck you COULD cook an amp IF your fuse is too big for your amp.

I'd love to keep this going but I know I'll get yelled at by ADMIN so I'll gladly help anyone that PMs me, including Diesel, or like I said before, take note of almost ANY big professional system.

It only took me two $1600 amplifiers to learn this lesson.

Oh, an cause I'm a d*ck, here is where Diesel copied that crap he found on google from:
http://www.audiogroupforum.com/csfor...ead.php?p=4668 (First post on that page, WORD FOR WORD)
http://www.caraudiohelp.com/newslett...citor_myth.htm

This is why there is so much BS on the internet. The people that actually know something and have their own experience and ideas have given up.

Do me a favor, if you plagiarize me, Diesel, put my stuff in quotes from now on.

Don't disrespect me by trying to pass someone else's work off as your own.

I'm out.

 

You mean the sites he copied any coherant sentence "he made" off of.

 

That was my post I copied

As for the formula, it was much easier to take it from there rather than type it up almost the exact same way.

 

Alright keep the down to a min...

All good info, Diesel does know his stuff and has proved it time and time again HCCAfan. I am not saying either is wrong or less qualified. But I know Diesels information is backed up as his own and he has helped in nearly every audio post on this forum. he knows his stuff

 

Did you even read what you copied? The formula is copied from a car audio newsletter. You must be a freelance writer when not working as a mechanic during the day and an electrical engineer at night.

As for the other guy you ripped off, he is out in South Dakota and that post was made 9 years ago.

 

My vote goes for Diesel

 

LOL Yeah ... Nevermind the fact that on page one he gave directions on how to do the (in his words) "big five" but then in this huge post he ripped off the internet he said (not really, but I'm playing along) never to connect anything to the battery.

Seems you have quite the following Diesel. Right on man. Right on.