Make Your Own Battery Cables

Making your own battery cables is easy and has several benefits over the ready-made cables you can buy from the parts store.

1. You can make much higher quality cables than you can buy.
2. You can perform a "Big 3" upgrade at the same time.
3. You can make your wires much neater and route them however you want.
4. You can future-proof your setup by making provision for additional electrical accessories later on.

For my car, I chose to integrate a "Big 3" upgrade at the same time. I also chose clamps with a wing nut lug that would allow me to disconnect the battery without using a wrench.

Here is what you need.

• Battery terminals (not pictured) - I can't find the ones I bought, but these are close enough: QuickCar 57-610 QuickCar Top Mount Battery Terminals | Summit Racing
• Red 4g wire (available in bulk from O'Reilly) - 3 ft.
• Black 4g wire - 4 ft.
• Red 8g wire - 2 ft. (not pictured)
• Copper 4g crimp terminals (also available at O'Reilly)
  
  • For 3/8" bolts - Super Start #01407
  • For 5/16" bolts - Super Start #08786
  • For 1/4" bolts - Super Start #01408
  
  
• Crimp terminal - 8g with a 3/8" hole (not pictured) - I can't tell you what to buy here because I used some that were given to me
• Crimp terminal - 8g with a 1/4" hole (not pictured) - Again, I used some that were given to me
• A hammer crimper for large gauge wires - PICO Wiring 0685PT Pico Lug Crimping Tools | Summit Racing
• 3/8" heat shrink tubing
• Wire brush (not pictured)
• Dielectric grease

https://www.dropbox.com/s/ypktxzo0eh...12929.jpg?dl=0https://www.dropbox.com/s/ypktxzo0eh...2929.jpg?raw=1


My battery cables weren't terrible, but I was dealing with a bad weak start condition that I eventually traced to this sad, sorry excuse for a ground wire that runs from the valve cover to the radiator support.

https://www.dropbox.com/s/s9t063w0et...3804.jpg?raw=1


It's too small and runs to a flimsy sheet metal brace on the body. That's just not enough to support the high amperage flows that a starter demands. The setup was barely adequate in '89, and by now, it might as well not be there. I decided to re-route it from the lift bracket on the intake to the shock tower. Both points have lots of metal to support a lot of electron flow.

Here is how I made the cables.

https://www.dropbox.com/s/08e0yekr6x...5232.jpg?raw=1


Spend some time thinking about how you want to route your wires before you cut your cables to length. Make sure they are neat, orderly and not in harm's way. When you crimp your connectors, you might be tempted to skip the hammer crimper and just bash the crimp connectors flat with a big hammer. I don't recommend this. The crimps will be exposed to a lot of heat cycling and vibration and could come loose. Spend the money and do the job properly. Finish up by protecting the crimps with a length of heat shrink tubing.

I made 4 wires.

• 1 red cable from the battery positive to the starter
• 1 black cable from the transmission ground to the body ground
• 1 black cable from the body ground to the battery negative terminal
• 1 black cable from the lift bracket on the intake manifold to the driver's side shock tower

https://www.dropbox.com/s/47ti4pi9zy...3329.jpg?raw=1


Take some time to clean up all the ground contact points on the car before installing your new cables. Wire brush them all thoroughly. Make sure there isn't any corrosion or paint to interfere with the flow of electricity from the car to the cables. Coat your clean contact points with dielectric grease and tighten them down.

Here is how I ran the new wires.

The transmission ground point and the starter positive -

https://www.dropbox.com/s/2im2f8t6rm...4952.jpg?raw=1


The body ground point next to the battery. One wire goes to the transmission ground. The other goes to the battery negative cable -

https://www.dropbox.com/s/p6h5q1erb1...4956.jpg?raw=1


The shock tower to intake lift bracket -

https://www.dropbox.com/s/8cv3astj3q...5011.jpg?raw=1


You're almost done. Be sure to replace the 8g wire that runs from the battery positive terminal to the underhood fuse box. It connects here -

https://www.dropbox.com/s/3swdflq7th...2600.jpg?raw=1


You're done! Take a step back and admire your work.

https://www.dropbox.com/s/g254i45dq6...5221.jpg?raw=1


After this upgrade, you'll notice much stronger starts and faster battery charging.

Since you've done such a lovely job with your new wires, let me encourage you not to clutter it up with a bunch of unnecessary haywires hanging off the battery positive terminal. Instead, as you add new accessories, like USB chargers, amps and the like, install an auxiliary fuse box and run your accessories off of it instead. You won't regret it.

https://www.dropbox.com/s/70d7t6syi4...2550.jpg?raw=1


Cheers!

Nice how-to man! Wish I seen this before i did mine, but i made it through lol

Nice job indeed. When I came onto this group, like about 3 yrs ago, I think your car wasn't running for a good while then. I assume it is now [emoji780] Hope so, an administrator like yourself without a running / driving car seemed odd to me [emoji854]. Good how to I had already replaced mine with aftermarket ones, which really appear to be similar to yours, but otherwise I would have done it this way.

Verstuurd vanaf mijn E5823 met Tapatalk

Bought, not build..[emoji39].https://uploads.tapatalk-cdn.com/202...5b4b4a20d3.jpg

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Quote:

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Originally Posted by AWH

Bought, not build..[emoji39].

---

LOL. Yours looks good. Over here, not only is the cable they use crap, but the location is crap too. It's a small, flimsy sheet metal piece. Even worse, that small, flimsy piece bolts onto another sheet metal piece before it bolts to anything more substantial. There is no good path from there back to the battery negative terminal. Again, yours doesn't look like that. Must be a pop-up lights thing.

Where did you find such nice cables, BTW? My aftermarket cables were crap and I got them from Napa.

Quote:

---

Originally Posted by AWH

Nice job indeed. When I came onto this group, like about 3 yrs ago, I think your car wasn't running for a good while then. I assume it is now [emoji780] Hope so, an administrator like yourself without a running / driving car seemed odd to me [emoji854]. Good how to I had already replaced mine with aftermarket ones, which really appear to be similar to yours, but otherwise I would have done it this way.

Verstuurd vanaf mijn E5823 met Tapatalk

---

It runs again! Truth be told, it ran the entire time. I thought I'd blown the engine in the infamous "Canola Oil Incident" SMH but I hadn't. I was jobless and dead-stinking broke at the time. I needed the truck to do odd jobs to get by, so I parked the Red Car for 4 years until I got another job with a long commute.

Now, I'm preparing to buy a Type-S RSX, which will eventually donate its K20 to the Red Car. How things change. Anyway, the car still runs and drives, still passes smog and drives like joy.

That's a nice surprise for a change. Glad you get to enjoy it again. Karma paid you back for the effort put into this community [emoji854]. How things change indeed.
Have a nice day.

Edit, I just ran into those ground cables on a car meeting. Scooped them.

Verstuurd vanaf mijn E5823 met Tapatalk

Hey Snooz,

Gonna get the parts and do this myself, cheers for a great how-to. My alternator post has been getting hot and my starts weak. Had a few questions about your equipment list:

Is the 8G wire for the alternator-to-fuse box cable? I was thinking about upgrading this to 6 or 4 gauge tbh.

Did you set the heatshrink using the lighter? Never thought to do that, always had to find a heat gun.

Are your battery terminals 8mm (5/16) or 10mm (3/8) for the eyelet crimps? wanna make sure I get the right combination of crimps.

(For anyone) If im upgrading the alt to fuse box wire to 4 gauge, can I use the same fuse?

Cheers!

The 8 gauge wire is for the battery + to fuse box wire. I didn't do anything with the alternator wire. If it's heating up, then I would look for corrosion on the ends. Clean them up and coat them with silicone grease and it will probably work great. The wire itself is probably fine, though a bigger wire couldn't hurt. If you do end upgrading it, add your knowledge to this thread, for sure.

Yeah, I've always used the lighter to heat the tubing. Heat guns cost too much.

I think the battery terminals use both sizes. To keep you from reversing them.

Not sure on the fuse question but I can't see why you'd need to use a different fuse.

The answer to that last question is yes, in fact you have to use the same fuse or a short will just have more current. I don't remember which wire that is though, make sure it is attached to the fuse box well, don't replace it just to make a bad connection.

Custom Battery Cables with Ends - Marine Grade UL1426 Tinned Copper

Chart on the bottom has the gauge vs amps. I would use the right side "underhood" chart since temperature is the factor in amp rating.

I would stick with the factory rated fuse unless you go up on your alternator output you should be fine with what the factory speced and upgraded wires.