rcurley55

I finally got around to upgrading the underhood wiring on my Civic. It's not that difficult, and should take a handy person a few hours to do it cleanly - start to finish.

So, let's first talk about what the magic 3 are, and why we upgrade them. There are three wires in your system that are vital to charging system performance:

1. Positive lead from alternator to battery
2. Ground from battery to chassis
3. Ground from engine to chassis

Factory charging systems were not designed to supply current to aftermarket accessories, such as amplifiers. The factory also cheaps out on the wiring, using the minimum effort and raw materials to get the job done.

When we start talking about choosing wire size, there are a few things to keep in mind. All wire has resistance - no one has made the perfect wire yet. When we think about passing current across a resistor, we will experience a drop in voltage from one side to the other. In our cars, it's important to provide our amplifiers and accessories with as much voltage is possible (for those of us with loosely regulated power supplies especially ).

As wire diameter increases, it's resistance decreases. So when picking a size wire, generally, we decide on an acceptable voltage drop for that run of wire. Then we look that current (measured in Amps) that the wire must transfer. Then, take a look at the length of the run. After these parameters have been examined, we can choose a wire of the appropriate diameter. Keep in mind, as the length of the run increases, the wire's ability to carry current decreases (keeping all else equal).

So with that booooorrring primer on basic physics of electricity, here's how to replace that Magic 3 in your car:

rcurley55

Let me preface this by apologizing for the dirty engine. This is my daily driver and after 50k, it's starting to look gross. I've never touched it, but looks like I really need to clean it bad.

Let's start with the grounds to the chassis. There are two grounds on my Civic Si that came from the factory. The first connects the radiator crossmember and a stud on the valve cover. The second runs from the chassis to a bracket on the transmission.

Both are made of crappy, small wire that is very stiff. I'd guess both runs to be between 6 and 8 ga. The transmission run is larger then the valve cover one...

rcurley55

So, here's what I decided to replace it with. 4 ga Stinger Custom Pro wire. I used simple crimp connectors (although you could use the set screw type as well) to make my wires.

I also covered the wires using some techflex to give some extra protection and to dress them up a bit. The ends of the wire are covered with heat shrink.

When crimping large connectors like 4ga and 0/1, I highly recommend an impact crimper. It's going to give you a stronger connection then many of the other popular methods (bench vice, hammer and chisel, etc...) Partsexpress.com carries one by phoenix gold, but it's over $40.

http://www.partsexpress.com/pe/showd..._ID=6297&DID=7

I found a generic one for about $15 - great tool for this kind of work.

So here's just one of my grounds compared to what came from the factory...

rcurley55

Here's my new ground in place. I used some clear silicon to seal the terminal to make sure that I wouldn't have any corrosion. It also helps to make sure that the connection will stay tight. I added lock washers to all of the connections to make sure that they stayed very tight.

rcurley55

Here's the second ground to the valve cover. Notice how I left plenty of flex in the cable so that the engin can move. If you look closely, you'll notice that I also have gound through the paint down to bare metal to get a good connection...

rcurley55

Now let's move to the positive lead from the alternator. From the factory, the Si comes with a 6 ga lead from the alternator to the factory fuseblock under the hood. There it's fused with an 80A fuse before it's connected to the battery.

I decided to leave the factory lead in place and connected for a few reasons. First, I know that this connection is secure. Second, if my aftermarket connection was to fail, the car will still charge the battery. I will fuse the aftermarket lead at the battery with an 80A fuse as well. Third, removing the factory lead is damn near impossible without taking half the car apart.

Here's a pic of the connector/wire added to the alternator. I ran this wire along with the factory lead, using zip ties ever 6" or so to keep it away from heat and moving objects...

rcurley55

Here's the new lead with the factory rubber boot installed to protect the terminal. I put a slit in the factor boot to slide around the second terminal and then used silicon to seal it all up.

It's tough to see, but I made a loop with the new wire (same as from the factory) that travels down from the alternator, then back up. This will wick any water from the terminal down the wire where it will fall off.

rcurley55

That's two of the trhee...I'll put up the rest tomorrow and open up the topic for discussion.

Please forgive any mistakes, it's late and I've spent the last week straight on the car.

arch iceman

Nice work rcurley! Not to mentioned an often overlooked step to upgrading an electrical system. Very clean wire assembly there with the nylon sleeving. Also great tip on the silicon and lock washers. Only extra thing I would have done would be to solder the connections during the wire assemble, but thats just the anal former wire rep side of me.

This is a great idea and demonstration by rcurley of the more expensive upgrade ground kits available from HKS or other companies being marketed from $80 to $140. Im sure rcurley's kit and self assemble costed much less than one of these kits, and allowed him extra flexibility in deciding how to route the cables for his particular application rather than a precut wire kit would have allowed him.

For anyone with the time to do this I highly reccomend it. Even without an aftermarket audio system this is definitely an upgrade. Companies that offer ground wire kits tout performance increases and better gas milage. Not only that, but how many of you have actually checked the condition of your stock ground cables?

As I mentioned before, this is one of the foundation steps to building a sound vehicle. Electrical upgrade 101. Upgrade all the weakest points and links in the electrical system, starting first with all easily accessible cables.

I gotta give you props on getting that alternator cable connected without taking off the entire alternator which is a pain. I think last time I upgraded I had to drop the suspension arms to get it out of there.

One question. How long approx did you make the ground cable from your alt?

rcurley55

First, I apologize for the lack of updates...I've been busy with school and the two jobs

He's alive?!?! Thanks!

Ummmm....there is no ground to alternator wire that I saw....I was under the impression that the alternator was grounded through the bracket that was directly bolted to the engine!