If you haven't heard of the big 3 wire upgrade before, it involves replacing some of your car's wires with a much larger size, which decreases the overall resistance of your electrical system. This can help with voltage drops and dimming if you have a powerful amp, and it also provides more stable voltage and a better current flow throughout your whole car. Maybe it even helps with our car's tendency to blow headlights, who knows.

The big 3 wires are: battery negative to chassis ground, engine block to chassis ground, and alternator to battery positive. I decided to do all 3 of these with 0 gauge wire. You can use 2 or 4 gauge if you want, but obviously bigger is better. I also decided to replace my battery terminals, since the ones Hyundai uses are crappy stamped aluminum, and mine were corroding like crazy. You can do the whole thing in about 2 hours, for less than $50.

<u>Stuff needed:</u>
10 and 12mm socket or wrench
Bench vice or some big-ass pliers
Utility knife
2 1/4" bolts and nuts, with 4 washers
4 feet of negative wire and 6 feet of positive, 0 gauge
4 0 gauge ring terminals
2 new battery terminals
Your choice of beer

I got all of my wires and terminals from ebay seller bag-boy. Before you get started, make sure to disconnect the negative terminal from your battery. I found it easier to just take the battery out altogether.

Ok, so let's start with the easiest of the three, the engine block to chassis ground. If you look right in the middle of your engine block you will see a bolt which holds on a metal tab. I have no idea what this tab does, but it makes a great grounding point. Take about 30 inches of your negative wire and cut 3/4" of insulation off both ends. Crimp a ring terminal onto each end. You can try this using pliers, but for 0 gauge wire it's much easier to use a bench vise. Squeeze each side a little bit, and then squeeze the whole thing until it's nice and tight. Then wrap it up in electrical tape.

Here is what it should look like:


Unscrew the 12mm metal bolt which holds the tab on, and then fasten the wire underneath it. This is what it should look like:


Now we need to find a good ground point. Over against the fender, you will notice some holes which Hyundai has drilled for us. A 1/4" bolt will fit perfectly through these holes, so go ahead and sand away the paint and primer around the hole. Then use your bolt to secure the wire, with a washer on each side.


Here is how I have the cable routed. It goes along the coolant reservoir tube, then bends around and follows the power steering tube. Make sure the cable won't get near the power steering pulley or belt, and make sure it's not too close to the exhaust.


Now let's do the chassis ground to negative. Unless you can figure out a way to attach 0 gauge wire to the stock terminals, you'll need to get new ones. Here are the ones I got, they have ports for 0, 2, and 2x8 gauge wires:


Simply cut off the old terminals, and then attach the wires to your new ones. The negative terminal has 2 wires going to it, one small and one large. The positive terminal also has a big and a small wire going to it. Make sure to cut off the wires as close as you can to the terminal, some of them don't have much slack.

On the driver's side you'll see a hole just like we used for the ground on the other side. Sand away the paint, and attach the rest of your negative wire, with a ring terminal crimped on the end. Then hook the other end into your battery terminal. See the tiny wire running parallel to the big one? That is the original chassis ground. Pathetic!


Ok, only one wire left to run. Looking down at your alternator, right next to the catalytic converter you will see several wires running into it. There is a little cap which covers the positive terminal. Flip this cap open, and remove the 10mm nut. Now take your positive wire, and crimp a ring terminal onto the end. Bolt this end onto the terminal on the alternator. You will probably need to jack up your car and get at it from underneath.

Once you put the bolt back on, the cover most likely won't close. I covered the whole thing with electrical tape to shield it.


Now run the wire up and over to the positive terminal on your battery. I ran mine across the radiator support, underneath where the hood support goes. You can adjust the foam pads on the hood support so that it doesn't pinch the wire.


Now hook the wire into the positive terminal, and you are finished!


I'm still a little bit concerned about clearance issues with the alternator wire, so I will be keeping a close eye on that. If you are really paranoid, you might want to fuse the wire near the battery.

As for the results... at my amp's power terminals I was getting 14.4V at idle, which would drop to 13.6 when the bass hit. Now I get a steady 14.4V at all times. If you have dimming, I would recommend this upgrade before getting a cap, a second battery, or anything else.

 

Wow.

Pretty damned nice mang. I have a few additions...

1. Use Heat Shrink tubing, not electrical tape. It'll stay in place and look much better.

2. If you strip your paint around the holes (there are more accurate ways to do that), make sure that you paint over the bare metal still exposed when you are done.

3. Upgrade your battery. Get an optima or Tsunami Optima clone. No reason going thru all of this if you aren't gonna get a good deep cycle battery anyways.

4. In your second picture, where you mounted the wire, no problems with it, but you want that tab facing up. That's so you can hook an engine hoist onto the engine to support it when working on the tranny or to pull it. Just a suggestion.

Very nice all around man, love that grounding terminal. I'm gonna have to do this ASAP. How much did it cost you? Are the terminals (Wire rings) gold or gold plated? What clearance issues are you worried about?

 

Yeah, I forgot to mention that I did put some silicone sealer over the bare metal. Rust under the hood is not cool. The clearance I am worried about is the hood pinching down on the wire when it's closed. I don't think it will be a problem, but I'd rather not have it short. The ring terminals are gold plated, and the battery terminals are platinum plated.

I did the whole thing for about $65, including shipping and all that. You could probably do it for cheaper if you get everything locally and use smaller wire.

 

Very nice.

Well, what you can do is get some chalk, or baby powder, dust your wire that you are worried about. Close your hood firmly, push down on it a bit, then open it again and see if it left any marks on the hood inside. If not, you are clear.

Did they have that in blue?

Fantastic job man, this is someone that read the DIY rules and followed them.

 

You can get blue wire, here is a link to the seller I used:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...872678&tc=photo

He does combine shipping, I paid $8.50 for wire + ring terminals + battery terminals.

 

very nice DIY, im gonna prob. do it soon. i also have another suggestion.

after crimping the ring terminals on the wire, take a blowtorch to biatch, right where the connection is. right after you take the flame off, push some solder in there, making sure it flows throughout the whole thing and provides a very nice contact. when the solder wont melt on it anymore, heat it up again to make sure it spreads.

 

Actually, I put solder in the ring terminals while it is being held upright in a bench vise. I heat the terminal till I have a puddle of solder in there and plunge the cable in the terminal. It creates a very good electrical connection. Be careful, though, solder will sometimes come spraying out and can burn you.

Very nice DIY, It seems to be a useful mod and it looks better too. I do agree with REDZ, use heat shrink on the ends, it looks so much better.

 

I got those same battery terminals off EBay (audiopipe). I got copper though. About $18 shipped per terminal I think, maybe more, but not much more. I just checked, and I used the same seller as spiceflow did.

 

very nice DIY, a lil over kill if ya ask me, i mean 0 guage ???? damn, you runnin like 5000 watts and 2 batteries or what???, i just hooked in series with 8 guage, the stock fenderwell grouond, to neg. term to engine block to intake manifold, to fire wall.

and it did help alot, i noticed the interior lights dimmed a lil less when the bass hit.

 

Redz, what's a better way to strip the paint around the holes. I plan on doing the very soon and I want it to look good.