Okay I have the class M wire bookmarked, the 1/0, how many feet would I need? The kit I have has probably around 20 feet, and it has the positive and negative terminals on the end. As far as the fuse holder, its just a normal 250 amp fuse holder correct? I'm not too electrical savvy so this stuff is decently ancient hieroglyphics to me.
I used a different ANL fuse holder, this one:
here. For some reason, Amazon has a terrible pic of it. This is what it looks like installed (it's the box to the right of the battery that the cable goes through:
As for the box and kit you got - what's the distance you plan on running the cable? The distance will dictate if you want to run the 1 AWG battery cable from the kit or purchase 1/0 cable. Here's a good
read from Crutchfield on gauges vs. power - they intended it to guide car audio amp selection but the information is still relevant. The summary is this: at 250 amps (your fuse rating), 1 AWG battery cable is good for runs up to about 13 ft (the chart shows 2 AWG, but you can substitue 1 AWG there). For runs of about 13 to 22 ft, you should go with 1/0. So it depends on the length of cable you will need. You can use string or other wires to get a good estimate of the run. Don't forget bends and contours to the body of the car, don't just pull the string in a straight line.
Assuming you want to purchase the 1/0 welding cable, use your measurements as a guide for how much to buy. For me, I bought 20 ft. I was able to run from the battery located on the rear little bulkhead thing behind the passenger seat, along the back of that bulkhead thing, up along the driver side sill, through a grommet in the firewall, up along the underside of the front fender (to a distribution block), and then continue to the front where the battery used to be (and where my jumper studs are now located.) Here's a series of pics showing the run. The cable is the thick orange cable (the thinner orange cable at the distribution block goes over to the starter):
I have about 7' 8" left over. Which means I used a little over 12 ft for my run. Now, in my case, I could have gotten away with 2 AWG. However, because the battery I'm using is puny, I wanted to give it every advantage I could, thus the 1/0. Make sure you get some split loom as well to wrap around the cable. In the pics above, I didn't. I just ran the cable because I figured the thicker welding jacket was good enough plus the cable was going to be under carpet and not near any moving parts, so the likely hood of it getting nicked or cut was very small. In retrospect, I still should have loomed it, because why not. It would have taken me an extra 2 min to do it. So make sure you do it, be better than me. (Though, once the cable entered the engine bay from the firewall, I
*did* loom it. In the engine bay, it
*must* be loomed. In the cabin, it
*should* be loomed.)
While buying the 1/0 welding cable, I also bought 4 AWG (20 ft) and 6 AWG (20 ft) as I was also replacing my alternator wire and my starter wire. I have a bunch of the 6 AWG and 4 AWG left over. For what it's worth, here's how I wired things, and what gauge I used:
If you are adding in a kill switch, it makes things
A LOT more complicated. The issue stems from your alternator and computer. If you just wire it up like a lot of diagrams on the net seem to show, you run the risk of sending a high current spike to your computer and frying it. Full disclosure though: I haven't wired in a kill switch. So I haven't tried it, and maybe you won't fry your computer. I don't know for certain. What I do know, is that that I was this close |--| to putting in a kill switch (even have pics of it mounted) and decided not to at the last second. The kill switch, though, is one designed for cars with computers, and sends the alternator to ground when engaged, thus protecting the computer. So if you are looking at a kill switch, you may want to consider this.
And for the ground for the battery, make sure you find a really good spot - try to use something like the trunk floor; something that has a lot of good welds and solid metal connections to the rest of the car. A frame rail is good too, if you can get to it. Make sure you remove any paint, and use a bolt with a lock nut if no stud is available. Do not ground into the flimsy sheet metal behind the wheel wells where the rear fender area is. Also, keep your ground cable as short as you possibly can.
Edit: Oh, I forgot to mention, don't run your cable outside of the car. Some people run their battery cable under the car along the frame rails or something. Don't do that. Keep the battery cable inside the car. You never know what you will run over or hit. It's just not worth it. Could you get away with it? Sure, maybe. I'm sure people have. But why risk it.
