Amp earth connection - body or battery?

[dest]

I know its best to have the earth connection pretty short when wiring in an amp, but is it best to earth directly back to the battery, or to the bodywork?
In the past Ive always used the body simply because its nearer than the battery under the bonnet, but on the Avant the battery is obviously at the back!

Any pros and cons for fitting to the battery? I would rather do that than start drilling holes...

[Jamo]

Always the body, if you earth to the battery you create another electrical route for the cars electronics components to pass current through such as the starter motor!

[topsparky]

Always the body, if you earth to the battery you create another electrical route for the cars electronics components to pass current through such as the starter motor!

i agree

[ctolladay]

If you wire from the -ve terminal of the amp to the -ve terminal of the battery then the only current passing along this path will be that of the amp (assuming that this is the only eathing path for the amp).

What you should try to achieve is the greatest possible voltage across the amps terminals. To do this you need to create two feeds which have the minimum possible resistance. Use the shortest possible runs of cable and use the thickest possible cable. The cars body can be thought of as a very thick cable but you must ensure that you get a good connection between the cable and the body.

You also must ensure that there is a very good eathing strap onto the battery. I would always suggest removing the strap (cable) and giving the connections a dam good clean. If you want to go silly then once the strap has been reattached to the body, use some lacquer to cover the connection to stop oxidation of the bare metal therefore maintaining a good connection.

[dest]

Hmm, so varying thoughts...

There is a nut/bolt at the and of the bar that holds the battery in place, am I guessing that would be no good to earth to?
Its very conveniently placed!
Otherwise, are there any other places close to the battery that could be used without having to drill a hole somewhere? (On an Avant)

EDIT: Found one

[Jamo]

Hmm, so varying thoughts...

There is a nut/bolt at the and of the bar that holds the battery in place, am I guessing that would be no good to earth to?
Its very conveniently placed!
Otherwise, are there any other places close to the battery that could be used without having to drill a hole somewhere? (On an Avant)

EDIT: Found one

Go into any ICE shop if you doubt my answer, I'm well into my ICE as members will tell you and have friends in the business.

All of them will tell you too earth to the body. Head over to www.talkaudio.co.uk

http://www.justkenwood.co.uk/editorial/faq_amp.asp

[dubmeister]

Found this:http://www.justkenwood.co.uk/editorial/inst_amp.asp

Some good tips, what you want is below:

How and where to earth your amplifier

The earth wire should be the same thickness as the power cable and must make direct contact with bare metal of the car.

Look for an existing bolt or screw that makes contact with the car body near the amplifier. Remove the bolt or screw, and scrape away any paint or grease. A star washer will help your earth wire maintain tight contact with the car body. Crimp or solder a eyelet terminal onto the end of the earth wire, slip it underneath the washer, and replace the bolt or screw.

If you can't find a convenient earth screw or bolt, drill a hole for one. Again, be careful not to drill into the fuel tank or a fuel or brake pipe.

Good luck

[dest]

Go into any ICE shop if you doubt my answer, I'm well into my ICE as members will tell you and have friends in the business.

All of them will tell you too earth to the body. Head over to www.talkaudio.co.uk

http://www.justkenwood.co.uk/editorial/faq_amp.asp

Wasnt doubting you atall, I just said there were varying opinions

I have now found a suitable screw and scraped the paint off...
Would of done that anyway, I just wondered what people thought of going straight to the battery as it isnt anything Ive thought about before as all my previous cars had it under the bonnet

[Jonas_R]

You always wire the earth to the body, never to the battery and remember to keep the length of the earth cable as short as possible. And remember you have to grind of the paint, so that you can see the raw metal in the body.

[S2central.net]

Earth to the body - always... as long as the body is metal and connected to battery earth of course. Think of the spaghetti of earth cables you would have if they were wired direct to battery terminals.

Paul

[pixsaudisex2]

see i have always conected my amps straight to the battery .. purely because ive always thought the battery was the earth on the car anyway making no difference ie its connected straight to the car anyway.. An i used to fit stereos for a living and its what they told me to do
an my system has been conected that way for three years no problems .
an i thought that stereo manafactures recommend you connect your stereos straight to the battery for less interference.. or maybe i just like to be different,,

[Fat Audi 80]

I have done the same as you after I had earthing issues on my amp. It has been like that for a few years also!

Works for me.

Cheers,

Steve.

[S-Express]

I used to have alternator interference when amp was earthed to chassis.
Once I took earth straight back to battery - all was ok.
When I was into audiophile level car audio (15 years ago now) the done thing / best practice was always told to earth directly to battery - never to chassis.

[Cullam3n]

Weird - was always taught to have the shortest ground cable possible

[Fat Audi 80]

Weird - was always taught to have the shortest ground cable possible

They are, going back to the battery in an ABY