Battery Terminal Wire Gauge Sizes

First time getting into the electrical stuff on the Tacoma so I apologize if this seems elementary. Does anyone know the wire gauges of the OEM battery terminal connectors? I got the mil-spec battery terminals and am planning to attach ring terminals to the wiring to make it work. These are the wires in question:

A) Wire from negative terminal to wiring harness
B) Wire from negative terminal to body ground
C) Wire from positive terminal to fuse box
D) Wire(s) from positive terminal to wiring harness (from what I saw on wiring diagrams, there are several wires in this bundle, would like to know gauge of each wire in the bundle unless anybody has had any success somehow combining this bundle into a single ring terminal)

Images of the wires in question for clarity are below:

 

Bigger is always better!

I use 01 welding cable for the positive to starter and all the ground connections .

The wire to the fuse block I never go smaller then 8AWG

maybe search big 3 upgrade

 

I saw the big 3 upgrade article with the 1/0 welding cable replacement and would like to do that eventually in the summer. But right now I just want to at least get the military spec battery terminals in so I need to know the OEM wire gauges to get the ring terminals on for now.

 

Sorry no clue !!

 

You can get an OEM replacement.

 

I am trying to avoid having to get an OEM replacement and just reterminate the wires at this time since I plan to replace the big 3 with 1/0 welding cable in a few months.

 

This is just my best guess.

A, B & C look like a #4
D - no way to even visualize. But I'm thinking #2

I'm quite certain that those cables are bigger than a #6. But smaller than #0. Process of elimination, that only leaves #4 and #2.

 

Hi @linw0724 sorry to bump your thread but did u find out the wire gauge sizes ? Any pics or write up if your battery terminal upgrade project ? I have some on the way and want to clean up the electrical as much as I can. Thanks !

 

Not yet, I'm waiting for the dual battery kit for the 2G Tacoma from Genesis Offroad so I can tackle the big 3 project at the same time. So for the moment, I do not have any measurements. Let me know if you beat me to it and get sizes

 

4 AWG sound right for cables B and C.
https://www.tacomaworld.com/threads...-box-battery-wire-replacement-upgrade.420450/

This link is to an earlier post shows you how to replace wire to fuse box (C). They measured the OEM fuse wire to be slightly smaller than a 4 AWG wire, probable a metric size. Your (B) cable should be same size as the fuse box wire.
I planning to do same for my taco and lengthen the cables at same time so I can switch to a front post battery. Haven’t measured the starter cable yet so also interested if anyone knows gauge and length for the two larger wires.

 

thanks @Desert Dog. I bought an Amazon 4 gauge cable from Spartan cables, made in USA and cheap. it is 12" long and I hope will work out. that's a small distance on the original OEM wire to frame tho ha. bending this 4 gauge is a tad difficult. I think the OEM may be a 6 gauge I heard someone say.

 

Also Check out BatteryCablesUSA, custom made to length in inch increments for smaller lengths and you get to select different terminal sizes for each end. I ordered on Sunday, had it in my mailbox by
Wednesday


Wednesday.

 

Hey @Desert Dog quick question apologies if this is a stupid one as I’m a electrical nOoB But can you heat shrink over heat shrink? I got a new battery cable for the ground and I’m putting the braided loom over it and wondering if it’s ok to heat shrink over heat shrink (meaning the lug already has heat shrinking over it as it came that way from factory). I’m attaching pics to illustrate what I’m asking. First pic is of the lug as it is. And the second pic I practiced heat shrinking the braided loom over the wire. Thanks !

 

Can’t think of a reason why not other than it fattens up the cable next to the lug. That might be an problem if the screw you’re bolting to is on a flat surface and now the lug won’t lie flat on the surface. A couple washes should fix that but my cause future problems if washers rust and weaken the electrical conductivity. Stainless steel washers should prevent that.

Also be sure to use the adhesive lined shrink wrap so the outer shrink wrap doesn’t slide off first layer. I like the look of the braided loom on your cable. I use similar loom on all my wiring. Makes it easy to differentiate OEM wiring from what I installed in case I need to rework anything.

 

@Desert Dog Is it easy to disconnect the 2 merging negative cables as in the image below ? Also when I’m attaching my new cable to the chassis ground, I’ve heard the OMM one has a special washer thing but mine won’t have that. Do i just go straight onto the frame with the lug ? This will be my first project like this.
Bought many diff sizes of loom and i guess u want this tighter rather than loose right? It’s split and I was planning to heat shrink over the braid. I don’t really love the shiny look of this but also have some Painless Performance Classic Braid loom coming too to compare looks. The 3/8” split loom fits on the 4 gauge the tightest but I did a 1/2” on my sample piece I tried. Does it matter or as long as 7 heat shrink u could go looser around it ?
I also have some Painless Performance classic braid coming to see as I like a more matte loom and this is seeming more shiny than I had thought on pics.

 

That is odd, my ground cable has 2 lugs on it with one end fitting under the bolt head on the battery clamp. You gonna half to cut that electrician tape off that junction and see what is underneath.

Don’t think I can give much advice on split loom. I only use the non split expandable loom. It typically will expand to 2X larger which allows it to slide over lugs and then collapse to a tight fit on the wire. Also comes in different colors if you want to go overboard and color code your harnesses.

 

What kind/brand and style do you usually go with ? And do u have any pics ? Thanks

 

I get mine from EBay, seller 225FWY, but there are other on EBay

search for expandable cable sleeving or braided wire loom.

here is an example. Both cables in picture are same “red” but one is new and the other, older one, faded to orange after 12 months. If you look close there is also a blue one coming off the side light.

 

Well. @Desert Dog i got it installed, but I was really concerned with my compression lug as I couldn’t get it to get tightened all the way on the base thread. Showing pictures below. When in started it after hooking both up, it was a weak first start but it starts and runs. Hoping it’s ok for the long term and won’t give problems. Any thoughts ?
1st pic is of the lug installed as far as I could thread. Didn’t wanna crank too far as the instructions said could strip. Also final pic is the completed install. Thinking I may try and reroute the top negative cable under the others to not be looped as high in the air. My install didn’t leave me much slack with the amp power wire for the positive.

 

Looks great! Don’t think a professional could do better. The SDHQ terminals adds a nice touch.

Did you use compression fitting for both positive and negative? I was going to replace entire cable but the compression fitting may be a good alternative. Any chance you have a link to where you bought them?