Replacing power cable throughout the car..

[nsxotic911]

I'm looking at replacing as much of the power and ground cables as possible throughout the car during a stereo upgrade. Here are the questions.

1. What power wire and ground from the battery to the hatch? 1/0? It's 10 years old, looks rusted etc.. Does the ground need to be the same gauge or thinner? I understand it should be the shortest.... If I replace as many of the standard grounds, what gauge?
3. Is it a bad idea to replace the power cable from the hatch terminals to the alternator? What gauge?
4. Usually, it's best to run power from the amp to the battery, rather than to an auxillary. In the NSX case, I can run it to the hatch terminals, but it adds a additional point of loss and resistance etc.. It will also be a little tricky with the fuse box cover.. especially if I this cable..I will take the weight hit if I have to run it to the battery to get teh best connection but if I don't need to, I won't.
5. When running grounds to a point, in theory, does it make a difference/is it better to run it to the battery ground as an aggregate? For example: the AEM Wideband calls to run the ground to the battery ground (if I remember correctly..)
6. Dumb question: Does power cable go to the speakers or the sub? And if so, what gauge. Sub will be mounted in the passenger footwell (ZETOOLMAN V3) and the amp in the trunk. AMP is a 3 channel PG Octane 800 watts total which will be powering 2 Diamond Audio HEX (or compareable) speakers.

I want a clean, 99% "no compromise" system when it comes to providing power to all the electronics.

 

[Cozmo]

I'm looking at replacing as much of the power and ground cables as possible throughout the car during a stereo upgrade. Here are the questions.

1. What power wire and ground from the battery to the hatch? 1/0? It's 10 years old, looks rusted etc.. Does the ground need to be the same gauge or thinner? I understand it should be the shortest.... If I replace as many of the standard grounds, what gauge?
3. Is it a bad idea to replace the power cable from the hatch terminals to the alternator? What gauge?
4. Usually, it's best to run power from the amp to the battery, rather than to an auxillary. In the NSX case, I can run it to the hatch terminals, but it adds a additional point of loss and resistance etc.. It will also be a little tricky with the fuse box cover.. especially if I this cable..I will take the weight hit if I have to run it to the battery to get teh best connection but if I don't need to, I won't.
5. When running grounds to a point, in theory, does it make a difference/is it better to run it to the battery ground as an aggregate? For example: the AEM Wideband calls to run the ground to the battery ground (if I remember correctly..)
6. Dumb question: Does power cable go to the speakers or the sub? And if so, what gauge. Sub will be mounted in the passenger footwell (ZETOOLMAN V3) and the amp in the trunk. AMP is a 3 channel PG Octane 800 watts total which will be powering 2 Diamond Audio HEX (or compareable) speakers.

I want a clean, 99% "no compromise" system when it comes to providing power to all the electronics.

Speaking from experience with car stereos but not the NSX specifically...

All that needs to go to the speakers is speaker wires from wherever your amp is. You'll probably want to use a pretty big speaker wire like 8 gauge, which can be tricky to run since it is thick.

Generally car amps are connected directly to the + terminal on the battery and grounded to whatever is convenient. The remote wire from your head unit controls switching it on and off. I think where you connect the amp's power really depends on how much power draw it is going to have and how big the cables going to the battery are from there. 0 gauge is enormous. If the wire from the hatch to the battery really is that big connecting to that would be just fine I imagine.

 

[Acura NsX Pilot]

Equal or bigger is always better but never go thinner. Use the correct fuse size and dont skimp on cheap cables.

 

[Malibu Rapper]

I wouldn't make a big project out of this personally. But here are a few pointers. Where you replace any OEM cable, you should go bigger and make sure the contact points are clean. A Dremel will come in priceless for this as you can finely sand down and clean the connections. It's important to go bigger because the original cables are not finely stranded as most high end power cables are. Because they are not as finely stranded, that means they actually have less resistance and therefore can flow more juice than a finely stranded cable of the same gauge.

Grounding at the battery is ideal but not necessary. That's why cars are manufactured with at least several chassis ground points. You can spend all month long replacing all your cables but in the end you won't notice much improvement if any. If your car isn't running good or has some electrical problems do what you can to fix those problems. You might create more problems trying to replace your OEM cables so I would adhere to the old adage "If it ain't broke..."

 

[nsxotic911]

Thanks guys, this helps a lot! I started the project and starting to rip out the crusty power wire going from my battery to the hatch. It's certainly not 0 gauge and a bitch!...but through time, I'll get it out

The problem I'm having is that it seems to go over the fuel tank.. and there are a few bolts where I'm not sure if I can undo. If I have to move heaven and earth, I'll get power back to my car, but it may mean fuel tank removal or..... running power in an alternate way.

Anyway, I'm stuck with 0 gauge which is absolutely ginormeous.... If I can succesfully bring it from teh batter to the hatch, what I'm thinking about doing is plugging it into a power distribution block, and then plugging that into the hatch battery terminals + the amp...

This is a bigger project, but as long as I don't end up with fuel all over myself, and/or burnt car, I'll make it through.

On a car with nearly 100k miles, I think it's not a bad idea to remove as many old hoses, grounds, wires etc.. that have crusted over time. For one, I saw that one of my grounds on the engine near the cam plugs, which I think plugs into the ignition coil/system, had all sorts of grime on it! That surely affected the signal quality even a bit, and if it is the ignition system, even a slight change can have drastic issues...


...............I'll try and have pictures soon..

 

[Butler]

You already got your anwser but if you wanted to get overly serious into this then....

as a rule of thumb, go one step larger gauge over stock components. In most cases just upgrading to better quality wiring will make the most difference. You don't want too go to large or small.

Like said above you can sand/dremel the area around the ground connection, I recommend covering the area and connection with dielectric grease to ensure the connectors don't oxidize as much over time.

if your really bored you can figure out the restistance of each cable for the power your putting through it and minimize the resistance, well then your golden... and insane. (or anal retentive)

 

[nsxotic911]

You already got your anwser but if you wanted to get overly serious into this then....

as a rule of thumb, go one step larger gauge over stock components. In most cases just upgrading to better quality wiring will make the most difference. You don't want too go to large or small.

Like said above you can sand/dremel the area around the ground connection, I recommend covering the area and connection with dielectric grease to ensure the connectors don't oxidize as much over time.

if your really bored you can figure out the restistance of each cable for the power your putting through it and minimize the resistance, well then your golden... and insane. (or anal retentive)

Working on it! I think I've settled on 1/0 gauge from the battery to a distribution block in my engine hatch. I'll connect my starter cable and the fuse box to it + the amp. They all seems to be 4 gauge and the hatch fuse box won't even take a 1/0 gauge.

..keep you posted..

 

[LJSB]

 

[KooLaid]

There is 2 gauge. Rare but available.

The finer the strands the better.

 

[omega2]

Recently the clamp on the starter cable that connects to the positive battery terminal snapped. The clamp would always appear loose and I thought the nut needed to be replaced since it was slipping due to the edges of the nut being slightly deformed. When I replaced the nut with a new M6-1.0 nut the clamp snapped when I started tightening.

I have read other posts on this forum where people cut off the broken clamp and bolt on an aftermarket one. I also talked to a local auto electric shop and they also mentioned the same procedure. That said, I would prefer a solder connection since it seems more permanent and I imagine better continuity. Additionally, I would like to have the same or a slightly longer length wire for the positive terminal cable (couple inches). My OEM wire is already pretty short and I fear cutting it shorter may make the battery installation more difficult.

So my options that I can think of are 1) replace the broken cable with the OEM cable or 2) make a custom cable; where the OEM is the easier option. Making the custom cable seems fairly easy, it's just a matter of getting the proper gauge wire, parts, and effort to solder everything together. Additionally, with the custom cable I don't have to deal with the flimsy OEM clamps again.

I tried looking through the owners manual and on this forum, but I am having trouble seeing how the starter cable goes from the battery (front of the car) to the starter (engine bay). On page 23-15 of the 1993 service manual it shows the starter cable, but does it go through the interior or under the car? Does anyone know where in the service manual it explains this replacement procedure or at a minimum has a better diagram? Or even better has anyone replaced this cable themselves?

 

[shawn110975]

LOL

TRUST ME when I say this replacing the Full cable from the engine bay to the front of the car is by far the longest process I have done.

I mean I can drop an NSX engine in less time.

In your case you need to cut the old connector off, then shave back about an inch of rubber on the wire. get the press clamps and get a chunk of wire same braid or brand and clamp the old wire onto the extension.

then put the new connector on and be done.

soildering the wire? well if your OCD about it, people have been doing this for years on cars not just the NSX. the crimping will be just fine.