Need Some Clarification on BIG 3

[jlc1991 0]

ok so i was just browsing some older topics today and realized that i have a wire kinda out of whack. im not sure if it is hurting or helping me or if it even has any effect at all. the blue wire (line) in the pic is the wire im referring to. its from my alternator negative to the negative on my second battery in the back. i have no idea what was going through my mind when i hooked it up like this but if im not mistaken, isnt it doing the same thing as if it were the negative on my battery up front to my battery in the back? also, one of my other questions was should i be running a power wire from the + on my alt to the + on my batteries in the back?? the way the pic is is how my wires are right now.

[PHATBOi 38]

The way you have it is fine. Actually I'm pretty sure it's better that way instead of just gounding the battery in the trunk cause then you are relying on the chassi of the car to return the current to the front batt. Your way is using the wire wich is a much more solid avenue for it to travel.

[PHATBOi 38]

Nice diagram btw. Totaly helped me understand what you where talking about. So much easier to help someone when they provide the correct info to work with.

[sefugi 166]

ok so i was just browsing some older topics today and realized that i have a wire kinda out of whack. im not sure if it is hurting or helping me or if it even has any effect at all. the blue wire (line) in the pic is the wire im referring to. its from my alternator negative to the negative on my second battery in the back. i have no idea what was going through my mind when i hooked it up like this but if im not mistaken, isnt it doing the same thing as if it were the negative on my battery up front to my battery in the back? also, one of my other questions was should i be running a power wire from the + on my alt to the + on my batteries in the back?? the way the pic is is how my wires are right now.

From the diagram I beleive you need: a fuse at the front and rear on the wire from front bat to rear bats

fuse between bat and alt front and rear

fuse between rear bat and amp

Nice diagram and you seem to be getting it done.

[jlc1991 0]

hey thanks a lot fellas! sefugi, i totally forgot to add in spots for the fuses lol. they are there on my truck i just forgot to put them in the diagram lol. btw thanks for the props to both of you. it took me like 10 minutes to do and it even helped me notice some things when i made it.

[Impious 1,476]

The way you have it is fine. Actually I'm pretty sure it's better that way instead of just gounding the battery in the trunk cause then you are relying on the chassi of the car to return the current to the front batt. Your way is using the wire wich is a much more solid avenue for it to travel.

Depending on his vehicle and the wire gauge he is using, the chassis may be a better conductor.

[sandt38 448]

The chassis is a better conductor, period. It has a surface area that becomes almost infinite in the circuit reducing resistance across it's path. You always want very short runs.

By completing the circuit from the rear battery to the chassis in the back, and having the ground from the chassis to the engine ground, you effectively have that circuit completed with a "larger cable" anyways. You want to reduce the resistance in ground circuits, as high resistance in ground circuits are what cause terminals to melt. Remember, contrary to popular belief, electricity travels from negative to positive.

In my GN I have a 1/0 run to the rear battery, and I cleaned the frame under the car and put a stud in the frame (just a bolt with a nut holding it in, threads out... using star washers and some silicone grease to prevent corrosion), and grounded my battery right there. I also grounded all my amps at that point to eliminate ground loop issues... hence the stud and not just a bolt holding it in

Also, I would directly run a ground from the battery to the alt as well... I should clarify, to any point on the engine really, as the alt finds it's case ground through the engine. I just prefer to ground to the alt bolt as it is usually pretty darned accessible.

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Of note, what you did is not wrong. It completes the desired circuit with an upgraded ground. But it could be done just a little better.