Power wire routing(through firewall)

[Dave Ladely]

I ran large guage 1/0 Marine grade wires from the engine compartment to the trunk by drilling a hole in the passenger fender and using a marine sealing type grommet, covered the wire with good garden hose to protect it, ran it under the floor back to the rear fender area, drilled another hole, with another marine sealing grommet. Ditto with the ground wire. Very clean, lots of capacity.
By the way, I used marine/aircraft quality 12volt breakers (Heart Interface) instead of dinosaur fuses. Came with a very hi tech panel. Also, has provision to label the breaker, and when the breaker opens, the label area changes color!!

 

[SHOZ123]

I used one #2 going to the trunk and I though I was adding too much weight. You used 2-1/0 wires? good grief. Kind of overkill to say the least.

 

[Dave Ladely]

I ran large wires for a rear mounted battery, to get low voltage drop and for high power stereo. No, its really not overkill by very much. For example, note the difference in power when jumping a car with 4 guage cables vs. 8 gauge. With 12 volts, even a relatively small voltage drop is noticable and the amount of current needed is large compared to higher voltage circuits such as home circuits, which is why manufacturers are going to triple batter voltage soon. I did not use the chassis for negative as that is a poor way to go.

 

[SHOZ123]

Yes I know about voltage drop. There is negligable drop with the # 2 wire I use. The only high current demand for the wire going to the through the wire is when starting where I still maintain a >12V while cranking due to the use of a deep discharge battery.

After over two years with the battery in the trunk I have had zero issues with using the body as a ground. The body is used as a ground in 99% every automobile electrical system. How many devices run the ground back to the battery?

40 feet of 1/0 wire has to weigh over 50 lbs doesn't it?