For the negative curcuit to complete itself, it runs like a spiderweb looking for the negative side of the battery, running thru all the welds and chasing peripheral runs. I highly recomended you run a short ground cable to the chassis AND then run your 1/0 to the engine block.
If you have a good positive with a 1 gauge or 1/0 run you can engauge the starting and charging system. Then use a positive block for your electronics. (Some manufacturers say to run their electricics on a seperate lead from the + side of the battery).
JPO - I do not believe in running welding cable. The large number of fine wires actually absorbes (reduces) amps, giving you a lower hit at the end of the run. In english....DC current runs straight thru the wire and several strands of larger copper wire handles the load better that dozens (hundred?) of strands of welding cable.
Last edited by oldandtired; 07-18-2015 at 08:30 AM.