Better grounding point?

[Steve@3dai]

Car frame, or car battery?

I'm considering redoing the wiring of my car, and want to do it right, and maybe even excessive (since I plan to keep the car a while).

[C-Man]

Always ground directly to the chassis of the car. Sand down all paint, make sure it's a clean shiny surface and make sure the ground is tight. Don't ground to the negative on the battery... if you look at it, the negative on a battery is about a 3 foot piece of wire running... you guessed it... directly to a spot on the chassis. In my opinion, which I think is a good one, that wire should be the only one connected to the ground side of the battery.

[Steve@3dai]

But if you look at it differently, are you grounding the battery to the car, or the car to the battery? ;)

So what if I skip the car frame and go right to the battery?

[Jstas]

No matter what, the battery get grounded to the car. Either through the engine ground or through the starter or through the charging system.

If you ground back to the battery you create a ground loop and that introduces a low frequency cycle and picks up virtually all other electrical noise.

Technically the car itself is not a ground because it is insulted by the tires. However, it's overall mass is sufficiently large enough that the charging system is physically incapable of over-powering the ground.

Also, if you ground to the battery and draw as much current as a car stereo does, you will end up blowing up the battery. It's not designed that way.

[Steve@3dai]

That clears it up. Thanks guys!