Sorry if this is an ignorant question. im not to up to speed with this kind of electronics so to speak.

When u install an amp it says not to connect the ground to the neg terminal on the battery.

really just wondering why not?

cheers

lach

Sorry if this is an ignorant question. im not to up to speed with this kind of electronics so to speak.

When u install an amp it says not to connect the ground to the neg terminal on the battery.

really just wondering why not?

cheers

lach

You want your ground to be as short as posssible. the neg battery terminal is connected to the shell of the car, so just drill a clean hole, rub it back, and screw the ground wire to it :)

oh yeah ive done that to mine. i was just wondering why not. so its just to keep ur ground short. wat is the reason for this?

So there is the least resistance back to the battery. The less resistance the easier the electricity flows

;1047251']So there is the least resistance back to the battery. The less resistance the easier the electricity flows

So the shell of the car offers less resistance than a 0 gauge directly back to the battery ?

So the shell of the car offers less resistance than a 0 gauge directly back to the battery ?

Should do, solid steel in comparison to copper strands?

You'll also find that you will get noise interferance through the speakers like a whine and changes pitch with the sound of the car.
You may also get the clicking sounds that rise or lower depending on revs.
Mate did it to his car years ago, and the clicking through the speakers ended up being the injectors firing and coming through.

ah i see.

Yeah i have a high pitch noise atm since i added a second amp. I read on here that by adding more ground points to the battery i should be able to reduce this

So the shell of the car offers less resistance than a 0 gauge directly back to the battery ?

200kilo's of metal compared to 4kg's of wire......
if running it back to the battery via cable was a better idea I'm sure carmarkers for the last 100 years would of ran EVERYTHING back to the battery via cable.

;1047295']200kilo's of metal compared to 4kg's of wire......
if running it back to the battery via cable was a better idea I'm sure carmarkers for the last 100 years would of ran EVERYTHING back to the battery via cable.

good point

Just to throw a spanner in the works......

In one car I've helped wire we have done a single point earth.

About to do another.

Then there's another drag car after that.

:)

However for car audio, its to keep the ground as short as possible.

I understand what everybody is saying, but the cars body itself inst the ground, its only grounded because its connected to the negative terminal of the battery ?

So the only reason we connect it to the car chassis is because steel is a better ground than copper ?

EDIT: Which after reading a few articles I'm inclined to believe that the chassis ground is NOT as good as grounding directly to the battery.

To have optimal wiring wouldn't you want the +ve and negative to have the same load on it all the time.

For example, you run +12v all the way to the boot, but you then use the chassis in the boot as the ground.

Think of all the other items in your car that are now and again using your chassis as a ground, lights, fans, indicators etc..

Why wouldn't you want your ground load to be uniform!?!?

DAM-088, short of a full re-wire in a car its impossible to connect everything to the -ive of the battery terminal.

Its optimal to have everything connected to that as it cuts out interference, stops 'earth issues' etc.

Currently when myself and a friend have finished wiring up a drag car, we did not run a 0AWG from battery (in boot) to the front and earth everything on one common earth. Now we're tracking down a possible earth issue. From now on I think we'll be doing that as standard on full re-wire's.

The body of the car is 40years old, and being freshly painted, fibreglassed, its getting difficult to find a 'good earth', which is causing a variety of issues.

That being said - earthing an amp to the chassis is not a concern IMO - its a lot easier and still gets the job done.

;1047295']200kilo's of metal compared to 4kg's of wire......
if running it back to the battery via cable was a better idea I'm sure carmarkers for the last 100 years would of ran EVERYTHING back to the battery via cable.

theres always those weird euro cars that use the chassis as +ve and run a wire for everything negative.

on the highpitched noise, is this just caused by a crap earth? i have it, my earthing point currently sucks, single pointed for the 2 amps, i guess i should just drill a new hole soon?

2nd gen guys, what are you guys using as earthing in the boot?

edit: will it be causing damage to amps etc if the earth sucks? or just an annoyance?

on the highpitched noise, is this just caused by a crap earth? i have it, my earthing point currently sucks, single pointed for the 2 amps, i guess i should just drill a new hole soon?

2nd gen guys, what are you guys using as earthing in the boot?

edit: will it be causing damage to amps etc if the earth sucks? or just an annoyance?

There is a hole on the drivers side behind the boot trims..... just behind the tail lights theres a bar thing...

Having a bad earth can cause issues with amps yes.

Its better to have two seperate earths for the amps - so one does not backfeed through another if one amp has a major fault, and does not take out your other amp while its at it.

cheers guys, will fix the earthing tomorrow then :)