battery relocation: why ground wire?

[acannell]

if i relocate the battery to the trunk, why do i have to run both a postiive and negative wire all the way to the engine compartment? why not just a positive? and then ground the "negative" wires in the engine compartment to some nearby sheet metal, and ground the batteries negative post to the sheet metal too, hence using the chassis instead of a second wire?

[fiater]

Who says you need to run the ground all the way back to the front? You can get a perfect ground on the frame rails in the back. I'm just bolting mine to the hatch floor after grinding the paint off. I'm bolting the existing front ground to the bottom bolt on the battery tray, just for extra continuity. You'll be fine, but if you want a super ground, drill a hole through the floor, pass the ground through and bolt cleanly to the rail.

[d_snook6]

When I had my battery in the trunk of my car I just ran the one wire back, and used the chassis for ground, worked great. But If your drag racing it makes no sense to have the battery in the trunk of a fwd car. I found a way to put it back under the hood.