How to beef up your alternator wire Options

[lagos]

The factory alternator to battery wire is pretty thin gauge. This could cause lower alternator output if you have a lot of accessories in your car. One solution to this problem is to add another fused wire from the alternator to the battery, as well as extra grounds from the negative battery to the chasis and the engine. This should help maximize the alternators performance and reduce the chance of dimming lights and other electrical issues.

Here is what I did...

I got some 8gauge power wire. Some people recommend using 4-0 gauge, but I think thats a bit of an overkill.



Then I got some copper ring terminals for 3bucks from pepboys. Crimped and soldered the connection and finished off with heat shrink tubing.



I also picked up a 60amp fuse and holder.





Wrapped up the wiring in black plastic insulation and electrical tape. Made sure to route the wire away from anything hot in the engine bay, and made the install look as OEM as possible. I didn't want some random blue wire standing out in the engine bay.




Connected the fused wire up to the positive battery terminal



And its all done..



This post has been edited by lagos: Dec 15, 2008 - 5:41 PM

[RickJamesBish]

Sounds like something I would need, I notice my dash lights dimming if I turn on the lights.

[presure2]

art, did you ever have a problem with that wire before? ( the stock one i mean)
im asking cause i know DG did your harness, and jims old 2nd gen harness which was done by him as well was shall i say..."less than perfect"..lmao that wire was a disaster, and was fixed by choping it back a good 8-10 inches, and resplicing it in a proper fashion.

[x_itchy_b_x]

i think its 3sgte thing or maybe harness related my stock alt wire disintegrated awhile ago and i did what are suggested here. good job.

[lagos]

art, did you ever have a problem with that wire before? ( the stock one i mean)
im asking cause i know DG did your harness, and jims old 2nd gen harness which was done by him as well was shall i say..."less than perfect"..lmao that wire was a disaster, and was fixed by choping it back a good 8-10 inches, and resplicing it in a proper fashion.

No.
DG didn't touch my alt wire at all.
Mine is all one section up to the fuse box where I soldered it in with the 6th gen fuse box wires myself. I added this extra wire because I'm noticing some lights dimming after driving around for a while with all the lights, heater, etc...on. I did a voltage drop test between the alt and the battery. Before adding the wire I had around .23v drop, and after it Im getting about .14, so adding this did help a bit.

There is a small issue with that wire on a swapped car. The original 3sgte alt wire is a very thick gague, but the stock 6th gen wire is much thinner. However there is really no way to replace the thicker wire into the new harness, because you would have to cut and solder it onto thinner wire and that would basically take away any benefits from doing so. Best thing to do is to keep the thinner factory 6th gen wire uncut and then add another wire like I just did if it is needed. Id actually be curious to hear what Tweak does with those wires when doing a harness.

This post has been edited by lagos: Dec 15, 2008 - 6:12 PM

[Promasta]

the big three
i did this with 4ga (not really overkill IMO)
the power wire to the alt
and the grounds to the frame and the block
it helped, lights are still dimming tho when system is up decently loud
i could get a really big cap, but i was talking to a guy in toronto that has the loudest car in NA, and he says that's not the way to go
might as well just get a high output alt off ebay
should do something before i kill another battery

i would post pics, but its -30°C right now

[lagos]

problem with those high output alt's is that they don't really put out any more amps at idle then a stock alt. So you could still have issues at idle.

I guess I should take pics of my other big 2... so that this can be a proper "big 3" write up.

[stephen_lee]

I have a pretty good system, 15 w/ 1200 watts RMS. stock alt to batt wire, but i do have 4GA (i know insufficient...) to the amp and some 4GA grounds, both replacing stock and added i believe two. NO dimming AT ALL. hardly any voltage droop, too. I do have a yellow top BTW. i did the grounds at the same time as i upgraded the grounds. I also upgraded my batt to starter wire to 4GA. i now have more powerful, quick & easy starts than before.

[lagos]

I think your 4gauge wire to the system is probably totally fine. The stock alternator wire to the battery is only something like a 8-10gauge wire. You would probably see some gains from upgrading that first.

The best way to know for sure if your wires are up to the job is the perform a voltage drop test.
http://www.excelauto.com/online/Tech.d/altvdt.html

This will tell you if you are loosing any power from having to thin of a wire.

This post has been edited by lagos: Dec 18, 2008 - 1:09 PM

[WWSideWinder]

Good one

I on the outher hand wanted to show my new ground cables.

New 8 Guage replacing OEM cables




New 4 Guage replacing OEM to Starter




New Distributer for 8 Guage cables



But as Allway Each to his Own those who Prefer to Show and those who prefer Stelth netheis better nor worse that the outher.

[lagos]

looks good.
you should do the alt wire too while your at it.

[d0w0rkS0n]

somebodies got T-Mobile. lol.


sorry couldnt help it.... at work on the forums...


oh... i work for t-mobile. guess that would help explain why i said something.


But nice thread Lagos! im gonna try this out

[Tigawoods]

did this fix your on going low volt problem?

[Cutrara]

big 3 ftw! I think anyone who has an amplifier you should do this. It only costs a couple bucks and improves your electrical system. At walmart they had 6 foot 4ga battery cables with a battery terminal on one end and a ring terminal on the other end. I bought 2 cables and a bunch of ring terminals and cut off the battery terminals.

[jcbass7]

I should do this alt wire, if anyone remembers mine caught on fire after my swap. The wire was incredibly brittle and i had to do the 8-10 inch replacement to fix the damage...

I still haven't figured out why it cooked like that

[lagos]

did this fix your on going low volt problem?

Id say I gained about a 1/2 volt from it. The main issue I was having is that my boost gauge wouldn't get enough voltage and would turn itself on/off at idle while driving. Adding this wire seems to have solved that.
However my safc voltage still reads lower then yours did. I believe part of the problem is because I don't have the factory fuel pump resistor pack (a swap thing) in place. The big supra fuel pump is just wired to run full blast off of the circuit opening relay, that also supplies the voltage for the ecu/safc.
I also noticed I loose about 1 volt from turning on my HIDs and fog lights.

[lagos]

I should do this alt wire, if anyone remembers mine caught on fire after my swap. The wire was incredibly brittle and i had to do the 8-10 inch replacement to fix the damage...

I still haven't figured out why it cooked like that

It seems to bee a common issue for swappers.
The factory 3sgte alt wire is a bit thicker, and when you are converting the harness to work in our car, you have to pretty much replace that wire with the thiner 5sfe wire. There is really no easy way around that.
Then add to the fact that we run our fuel pumps constant, and get a billion and one gauges in the car, and you end up with a lot of current going through that thin wire that could cause issues down the road.

[99GT]

My battery light came on. Both of my wires were cooked this weekend (wires thats goes onto the alternator. They were barely hanging on. One was totally off. I replaced the wires already, but its back to burnt crisp again.

I checked my alternator and is putting high .8 higher than normal when I took it into Checkers. Could my alternator be the reason by putting more output trying to charge the batter, causing heat, hence the cripsy wires?

I think it would be the alternator since I already replaced new wires. Am I correct?


my previous thread

Looks like I'll be doing the big three.

How much wire (feet) will I need to do the big three?

Should I get OEM Toyota Alternator? It's only a $10 difference from Oreilly, Autozone.

This post has been edited by 99GT: Dec 22, 2008 - 8:27 AM

[Batman722]

Art, why did you use a 60a fuse ?

[lagos]

the fuse holder can only handle a max of 60amps. The alternator puts out 80amps, but this is only a "helper" wire, so it really wont have that much flowing through it most of the time.

[99GT]

Would a higher or lower fuse be betteR?

[Batman722]

from the battery the + goes to the 100amp alt fuse then goes to the alternator. All the rest the fuses/relays see 60amp and lower.
The fact that a stock M/T GT alternator is 70amp and an auto GT alt is 80amp, the 100amp fuse is there just to guard against any power surges that's over 100amps. IMO I would go for atleast and 80amp fuse, or even 100amp, just like the stock system and to make sure you're getting the maximum amount of power the alternator is producing. Anything higher than a 100amp fuse that would be bad.

[Promasta]

[lagos]

Promasta, I hope you used a fuse!

from the battery the + goes to the 100amp alt fuse then goes to the alternator. All the rest the fuses/relays see 60amp and lower.
The fact that a stock M/T GT alternator is 70amp and an auto GT alt is 80amp, the 100amp fuse is there just to guard against any power surges that's over 100amps. IMO I would go for atleast and 80amp fuse, or even 100amp, just like the stock system and to make sure you're getting the maximum amount of power the alternator is producing. Anything higher than a 100amp fuse that would be bad.

The fuse size you go with, should depend on the gauge wire that you use. 0-4 gauge would probably be good to use with an 80-100amp fuse, and 8 gauge would probably work best with a 60amp fuse. You also have to see what is the max fuse size for the fuse holder you use. In my case I used 8gauge wire with a 60amp fuse, and its been working great ever since.

I personally think that the 100amp fuse toyota used was way too much. One can argue that they must know what they are doing, but we have seen cases of melted alternator wiring, and the 100 amp fuse never blew. This should never happen.

[Promasta]

haha nope.
car hasn't burnt to the ground yet.
but i will put an 80 amp fuse in this week.

[92-gt]

Approximately how much wire did you use? (ft.)

I am thinking about doing this because I have a new alternator on the way, and I might as well do it while I am replacing the alt.

[stephen_lee]

i used three feet i think. not very much. autozone switch to starter cable FTW

[stephen_lee]

here is my set up.

[92-gt]

Also, did you just leave the factory alternator power wire, or did you disconnect it?

And if you did disconnect it, did you remove it from the car or what?

Thanks,
-Ryan

[stephen_lee]

Also, did you just leave the factory alternator power wire, or did you disconnect it?

And if you did disconnect it, did you remove it from the car or what?

Thanks,
-Ryan

We just added a "helper wire." Which means we left the stock wire as is.

[92-gt]

I finished this a couple days ago on my 5th gen. I used 4 gauge for the alternator power wire and 8 gauge for my grounds. For the power wire I used a 70 amp fuse. I got a pretty nice fuse holder that actually has a digital volt meter built in to it.

I will get pictures up tomorrow.