2G Alternator Wire Upgrade Route

[Kai Hefner]

Going to upgrade my alternator wire for a rewound 110A alternator tomorrow. I'm under the impression that all I have to do in terms of wiring upgrades is to add some 4 gauge welding wire on top of the old alternator wires.
I was wondering, could I route my new wire straight to the battery instead of to the fuse box then to the battery?
How much wire do I need?

 

[motomattx]

No, you need a fuse between your alternator and battery or battery and anything else or alternator and anything else, you could go direct to the battery if you plan to install a fuse in between.

 

[Kai Hefner]

Okay will do.
Still looking for the length of wire from the alternator, through the stock route to the fuse box.
Another question, for a 110A alternator, should I get a 120A fuse? Currently have a 100A one.

 

[motomattx]

You want your fuse to be slightly smaller than the maximum load that the alternator is listed for as far as Im concerned, I would rather blow a fuse than an alternator, also your fuse needs to be small enough to protect the wiring for the circuit that its in, so if your using wire that is rated at 100 amp max, I would run a 90 amp fuse.

 

[llxkevinxll]

Also remember a 110A alternator has 110 Amps of capacity, it won't provide 110A constantly. Current is like a rope, it is pulled, not pushed. I would replace the double factory 8 gauge with a single 4 gauge wire (135 amps max) to the fuse box and leave the factory fuse as is. 4 gauge wire is good for 135 amps max. If you blow that one then consider moving up. I am using an Acdelco alternator to the factory fuse while powering a Spal 12", a secondary 12" fan, Bluetooth head unit, headlights, gauges, rewired fuel pump etc. and the fuse has never been an issue.

 

[chrysler kid]

Fyi if you wired every circuit to draw power it would not equal 100amps. There is never any reason to add a larger fuse. There will never be an electrical draw to exceed that rating where you need a larger fuse.

It's 3.5 feet from fuse box to alternator and maybe 6 inches fuse box to battery

 

[Kai Hefner]

Just want to follow up this thread, thanks all for the help. Did this a while ago, but I want to complete the thread for future DSMers.
Got a 115 rewound alternator in and some sick welding wire from the alternator eventually to the battery. My last impression might have been the car dieing on the side of the road/placebo but an alternator seems to make a world of difference in how smooth my car is running.

FYI following the stock route, the alternator wire was about 6.5-7ft in total length.

 

[ishnish]

I'm about to replace my stock 2g alternator with a 97 Galant alternator because my car's battery at idle goes up to 12.6 or so at the highest and the alternator goes to 13.9 or so at the highest .

I have the factory wires from alternator to fuse plus added a 4awg wire to fuse box and a 4awg wire from fusebox to battery in the trunk. I'm wondering if running a ground wire straight from the alternator to the negative battery post will help in the voltage increasing. Or would it be okay just to ground alternator to the chassis up front?

 

[llxkevinxll]

I'm about to replace my stock 2g alternator with a 97 Galant alternator because my car's battery at idle goes up to 12.6 or so at the highest and the alternator goes to 13.9 or so at the highest .

I have the factory wires from alternator to fuse plus added a 4awg wire to fuse box and a 4awg wire from fusebox to battery in the trunk. I'm wondering if running a ground wire straight from the alternator to the negative battery post will help in the voltage increasing. Or would it be okay just to ground alternator to the chassis up front?

Typically the alternator just grounds to the block. It won't hurt to ground the alternator body to the chassis I suppose but shouldn't be necessary.

 

[Kai Hefner]

I'm about to replace my stock 2g alternator with a 97 Galant alternator because my car's battery at idle goes up to 12.6 or so at the highest and the alternator goes to 13.9 or so at the highest .

I have the factory wires from alternator to fuse plus added a 4awg wire to fuse box and a 4awg wire from fusebox to battery in the trunk. I'm wondering if running a ground wire straight from the alternator to the negative battery post will help in the voltage increasing. Or would it be okay just to ground alternator to the chassis up front?

Sounds like a lot of unnecessary wiring. Just ground to the nearest good grounding point. The positive alternator wire is responsible for keeping your voltage up, invest in some decently sized wire.

 

[ishnish]

Typically the alternator just grounds to the block. It won't hurt to ground the alternator body to the chassis I suppose but shouldn't be necessary.

This is what I hear. Yet I have horrible voltage issues. Bummer but thank you

Sounds like a lot of unnecessary wiring. Just ground to the nearest good grounding point. The positive alternator wire is responsible for keeping your voltage up, invest in some decently sized wire.

I didn't realize that part as I thought grounding would help with getting that voltage up . Maybe it's my alternator. Thank you nonetheless. Oh and btw, I have two 16 awg and one 4 awg from alternator to fusebox, then 4 awg from fusebox to distribution box, and 0 awg wire from distribution box to positive battery terminal. So I'm sure I have plenty of good wiring .

 

[Kai Hefner]

Wiring sounds good. Voltage issues are likely alternator, if not just a crappy battery. If it's crappy battery try to trickle charge it to revive it. If it's alternator, look into places around you to get your alternator rewound for a higher amperage. I was about to go the route of getting a Galant alternator but I called a shop and for $100 he rewound my stock alternator (no fab required) to 115A. Perks of doing this as well is that the alternator has new bearings, a new pulley, coils and he cleaned it up on the outside so it looks like I have a brand new alternator.

 

[tayschells13]

On a 2g is it possible when relocating the battery to the trunk and rewiring the alternator to bypass the factory 100amp alternator fuse and just run a 1/0 gauge or 4 gauge wire straight from the alternator back to the battery with an in-line ANL fuse? Or is everyone recommending to just use the factory 100amp fuse in the fusebox?

 

[Kai Hefner]

On a 2g is it possible when relocating the battery to the trunk and rewiring the alternator to bypass the factory 100amp alternator fuse and just run a 1/0 gauge or 4 gauge wire straight from the alternator back to the battery with an in-line ANL fuse? Or is everyone recommending to just use the factory 100amp fuse in the fusebox?

Haven't done my battery relocate yet, but I'm curious as to why you don't make a common point in the engine bay for stuff that goes to the battery, then just have two lines, positive and negative go through the car to the battery. Basically for when you change an alternator wire or something, you only have to wire it to the common point instead of stretching the length of the car.

Is this what people usually do?

 

[tayschells13]

I’m in the process of doing mine now while using a kill switch in the rear by my license plate. The only two wires running through my firewall though are for the battery positive/starter and alternator, and I’m using a distribution box. I’m pretty much following turbosax’s diagram which I feel is overkill for my intended use. You don’t realize how tight everything is by the fusebox though until you’re in the process of doing it. I had to trim down my connectors quite a bit at the fuse box to squeeze (2) 4 gauge power wires in there, which is why I’d prefer just to bypass the factory 100amp alternator fuse and use an ANL in line fuse.

 

[llxkevinxll]

I’m in the process of doing mine now while using a kill switch in the rear by my license plate. The only two wires running through my firewall though are for the battery positive/starter and alternator, and I’m using a distribution box. I’m pretty much following turbosax’s diagram which I feel is overkill for my intended use. You don’t realize how tight everything is by the fusebox though until you’re in the process of doing it. I had to trim down my connectors quite a bit at the fuse box to squeeze (2) 4 gauge power wires in there, which is why I’d prefer just to bypass the factory 100amp alternator fuse and use an ANL in line fuse.

When you say the alternator wire is passing through the firewall, what do you mean? Wouldn't the alternator hot go to the fuse box under the hood? Then fuse box to hot post under the hood.

 

[tayschells13]

I have my battery relocated to the trunk, and have pretty much followed turbosax2's battery relocation diagram to a T although it's overkill. I know a lot of people in the past have posted that they utilize the factory alternator wiring and 100A fuse located in the fuse box. My question was, are people having success running a 1/0 or 4 gauge wire directly to the alternator and bypassing the factory 100A fuse using an in-line ANL fuse like shown in the diagram attached?

 

[Kryndon]

Looks like this is the most recent thread about alternator wires so I'm gonna jump on here also.

When I want to install a bigger size wire from the alternator to the battery in hopes of getting more volts (less volt drop), should I just leave the factory twin white wires in place and sandwich my new thicker (4ga?) wire on top of it? Or should I completely remove the factory charging wires?

Also, should I route the 4ga wire from Alt to Alt fuse, then from Alt fuse to battery +, or should I go straight from Alt to battery +?

Basically all I'm looking for is a quality of life improvement for the Alt. It's a good alt (stock 75Ah unit) but the wires that come off its power terminals are very stiff, don't have good insulation and I'm running an aftermarket O2 housing which radiates even more heat. Also, at full boost high loads, ECMlink shows 13.3-13.4volts. So should I just add a 4 or 6 gauge wire or would that not be necessary?

 

[Kai Hefner]

Looks like this is the most recent thread about alternator wires so I'm gonna jump on here also.

When I want to install a bigger size wire from the alternator to the battery in hopes of getting more volts (less volt drop), should I just leave the factory twin white wires in place and sandwich my new thicker (4ga?) wire on top of it? Or should I completely remove the factory charging wires?

Also, should I route the 4ga wire from Alt to Alt fuse, then from Alt fuse to battery +, or should I go straight from Alt to battery +?

Basically all I'm looking for is a quality of life improvement for the Alt. It's a good alt (stock 75Ah unit) but the wires that come off its power terminals are very stiff, don't have good insulation and I'm running an aftermarket O2 housing which radiates even more heat. Also, at full boost high loads, ECMlink shows 13.3-13.4volts. So should I just add a 4 or 6 gauge wire or would that not be necessary?

I was told that you can just leave the factory wires and install the 4ga overtop. Electricity travels through the path of least resistance, so most of it will end up traveling through the 4ga, but the white ones will still be hot. It's up to you.

You should route the 4ga Alt->Fuse->Battery. I've seen straight Alt->Bat before, it's not the end of the world but it is not the safest alternative. I've ran Alt->Bat in the past with no issues at all; however, vehicles have a fuse between every single electrical device... I wouldn't advise deleting the only one for the battery.

I don't think your logged voltage is too big of an issue. If you want something easy, you might as well throw the 4ga on top of the alternator wires, it will help. O2 housings on our cars really cook the alternators, which is why DSMs have so many alternator issues. Although it would be a good idea to take precautions with the 4ga wire, and insulate it, the more likely scenario will be that your alternator burns out before your wires can't stand the heat anymore.

 

[Vegas Smith]

Ideally you would add the size of wire needed to carry your max amps to distance traveled

Battery Wire Size Chart for Battery Wire to Alternator

Battery wire size chart based on the length and wire size, battery wiring diagram. Helps you determine the minimum battery wire size needed.

alternatorparts.com

For example, I have a 200a alternator and the battery is relocated to the back so that's a ton of amps at a long distance. I think I needed 2/0 awg wire which is huge. I would just do away with the stock wiring and run brand new wire with a fuse/breaker as close to the battery as possible. I run a breaker instead of a breakable fuse so that I can just press a button and the entire car is without energy when working on projects. I'm no professional but just the things I decided on. Because your alternator isn't that high of an amperage you could just run to the stock alt fuse and then to the battery and call it a day.

 

[talonesi95t]

Want to add my .2 cents, I just relocated my battery to the trunk. I used 2 gauge for my positive wire. I have one connection point where the stock battery was. Stock alternator wiring to fuse box, using a galant 100 amp alt. now from the fuse box to new connection point i replaced the wires with 8 gauge wire. There's the stock ground from starter to a bolt hole where the old mount was for the battery. I then added another 4 gauge ground from side of the head to another bolt hole left by the old battery mount. My battery is ground in the trunk. I sanded paint away at my ground points. Before all this my voltage was at 13.4 cold start and after warmed up drop down to 12.8. would drop more if i turned on lights. Now I get a steady 14.6 volts at idle and drops to 14.4 warmed up. I believe the grounds are very important part of any electrical circuit.