Will a High Output Alternator Fry my car's Electrical System?


taysextreme

Want some Come get some
10+ year member
Dec 7, 2007
338
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jersey
bigbang is right, but the power is pulled in the direction it is needed so there is no need to worry about it traveling through elsewhere

 

InfinitePeace

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Feb 3, 2008
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Sarasota, FL
Mine is being installed in the morning. I bought a 180a from Ohio General and they told me more than once, upgrade to the largest size of cable that you can for everything more or less EXCEPT the Alt to Batt Pos. They told me, which I confirmed multiple times, on a short run, 4awg (at least for upwards of 200a) is plenty and ideal; they don't recommend larger than that in that location because the size of the post on the alternator is too small to bind to the larger wire; ergo because of the size difference, the post on the alt heats up too much and can overheat it. That was their recommendation and I'm going to have the shop that is doing it for me talk to them and confirm with a detailed description of my specific engine.

The other interesting thing they said was do NOT fuse that wire. I confirmed this as well, DO NOT fuse this wire because if for some reason it does indeed blow, the alternator will no longer see the battery and think that it's dead, so it will kick into high gear and stay that way until it burns up because it will never see that battery again until you've changed that fuse, thus leaving you with a dead battery and a burnt out alternator.

Discuss.

 

ffkk

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PTA, RSA
//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif
 

Papaloads

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Feb 21, 2008
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LA, CA
The other interesting thing they said was do NOT fuse that wire. I confirmed this as well, DO NOT fuse this wire because if for some reason it does indeed blow, the alternator will no longer see the battery and think that it's dead, so it will kick into high gear and stay that way until it burns up because it will never see that battery again until you've changed that fuse, thus leaving you with a dead battery and a burnt out alternator.

Discuss.
I am no expert at all but from what i gathered on this thread it appears that putting a fuse on the wire from the battery's positive terminal to the Alternator WILL NOT affect anything ASSUMING you leave your ORIGINAL factory installed wire from the battery to the alternator.

If you do not remove that original wire then there shouldn't be any concerns about the "alternator no longer seeing the battery and thinking it's dead"

Experts please confirm or correct my above statements!

 

missinglink

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May 6, 2008
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Las Vegas , NV
I have 2 Ohio alts. I will agree NEVER put a fuse between the alts and battery. Your alternator needs to read a draw if the fuse goes your alternator will compensate. I have 2 1/0 gauge from one and a single off the other. 1/0 wont heat up as much as the 4gauge if your having alot of draw. Much over 1,000 watts I would go with the 1/0. Granted your alt will only put out so much power. (this is why 4 gauge is enough) If you are running 1/0 to your amps its wise to run 1/0 from the source.

MLA

 

lostforawhile

Junior Member
10+ year member
May 9, 2008
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georgia
ok another one, tell this to the people who tell you this crap, the alternator and the battery are connected together on the same circuit, the battery can produce way more current then any high output alternator ever can, so why aren't the electronics fried? //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif all regular alternators for automotive use produce the same voltage,or close to it. they can just produce more current on demand. with a HO one. one thing to look for is where your alternator is connected to the charging system. if it has a fusible link at the fuse box, you need a better connection point for a HO one, good place is run a 1/0 or 2/0 wire from your battery to your starter,then connect the alternator lead wire to the starter terminal also. this is good for your starter also,as this is a lower resistance path from the battery. thats means more current at the starter if it needs it.

 

lostforawhile

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May 9, 2008
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georgia
Here is my ? about the wire that runs from the batt to the alt?This is on a 94 civic

Do I take away the factory wire that runs from the fusebox to the alt?

I'm gonna use 1/0 gauge wire from the batt to the alt.

I just run the wire directly to the alt from the batt terminal?

See the civic has a little wire that runs from the fuse box to the alt, there is a wire that runs from the batt to the fuse box so i'm just trying to figure out what the deal is.

Any help would be nice if you need a picture of what I'm talking about let me know.
get rid of the stock wire from the alternator to the fuse box if you are going high output. run a 1/0 or 2/0 battery wire to the starter motor,then use the starter lug to attach your heavy wire from the alternator. good connection point.

 

missinglink

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May 6, 2008
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Las Vegas , NV
I have never changed my starter wire size and I run 13batteries & 20,000 watts. Why is the starter a better point? Why is from the alt to the starter to the battery better then straight from the alternator to the battery? You have me confused please explain more.

Sorry I'm not sure about the starter re-route. Why wouldn't he just upgrade his alt to batt wire. All other wires will see the same thing regardless where its routed if his fuse box is from the battery or the alternator it will read the same. It might be safer from the battery though. Bail the line from fuse box if something don't work you might route it to the battery.

As it may have a separate purpose.

MLA

 

missinglink

Member
10+ year member
May 6, 2008
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Las Vegas , NV
We looked into this little wiring question. Its a 80amp fused and a load sencing wire, keep that wire and add a 1/0 from the alt to the battery. I know why he was saying to the starter its closer may save some wire.(sorry I see why) It will have the same effect either way...

 

lostforawhile

Junior Member
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May 9, 2008
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georgia
I have never changed my starter wire size and I run 13batteries & 20,000 watts. Why is the starter a better point? Why is from the alt to the starter to the battery better then straight from the alternator to the battery? You have me confused please explain more.
Sorry I'm not sure about the starter re-route. Why wouldn't he just upgrade his alt to batt wire. All other wires will see the same thing regardless where its routed if his fuse box is from the battery or the alternator it will read the same. It might be safer from the battery though. Bail the line from fuse box if something don't work you might route it to the battery.

As it may have a separate purpose.

MLA
well i was saying to run it to the starter because it's easy to add the wire to the starter lug, then it will connect right to your battery through the terminal. this way if you have to add an extra wire it's eaisier then trying to add it to the battery terminal. it also looks a lot cleaner.

 

missinglink

Member
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May 6, 2008
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Las Vegas , NV
Yea we saw why you said it. You made a good point sorry mane. We see how you have to route it and it would work either way. I was just confused till we looked up the engine diagram. Than for the answer and not for the chewing LOL. Thanks for the point If I do a similar car I will keep it in mind.

MLA

 

shizzzon

I am who you think I am
10+ year member
Apr 27, 2008
1,294
6
KY
I've been told that if you have a HO alt installed and if your starting batt dies and ever got a jump, you must be extremely careful for the next several minutes.

If the engine rises above idle rpm, the alt will start to send gigantic amounts of current to your almost dead battery. If you have a 300A alt for instance, it will try to send all of it's power to your battery which will end up killing it because that is too much current to charge a batt.

The best thing to do is keep the rpm as low as possible and that way is to just keep idle for a while. IF you get no output at idle, barely rev it up and keep it there. Alts max out at 2k rpm engine rpm so it doesnt take much to be at risk.

 

Jando86

CarAudio.com Elite
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Jan 24, 2008
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ekectrile.

LOL

 

lostforawhile

Junior Member
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May 9, 2008
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georgia
Mine is being installed in the morning. I bought a 180a from Ohio General and they told me more than once, upgrade to the largest size of cable that you can for everything more or less EXCEPT the Alt to Batt Pos. They told me, which I confirmed multiple times, on a short run, 4awg (at least for upwards of 200a) is plenty and ideal; they don't recommend larger than that in that location because the size of the post on the alternator is too small to bind to the larger wire; ergo because of the size difference, the post on the alt heats up too much and can overheat it. That was their recommendation and I'm going to have the shop that is doing it for me talk to them and confirm with a detailed description of my specific engine.
The other interesting thing they said was do NOT fuse that wire. I confirmed this as well, DO NOT fuse this wire because if for some reason it does indeed blow, the alternator will no longer see the battery and think that it's dead, so it will kick into high gear and stay that way until it burns up because it will never see that battery again until you've changed that fuse, thus leaving you with a dead battery and a burnt out alternator.

discuss.
um the factory fused it for a reason, also the reason a lot of cars have fusible links,you may have a fried alternator but you won't have a burned car. i've worked with automotive electricity for twenty years as a serious hobby and sometimes profession,and thats the stupidest thing i've ever heard. that factory fuse or link is there to keep a dead short in the alternator from setting the battery cable to it on fire, screw the alternator,if that link or fuse goes you've got worse problems.

a short run, 4awg (at least for upwards of 200a) is plenty and ideal; they don't recommend larger than that in that location because the size of the post on the alternator is too small to bind to the larger wire; ergo because of the size difference, the post on the alt heats up too much and can overheat it.
what are these guys smoking? you crimp a terminal on end of the two gauge cable that fits the alternator post,the alternator isn't going to overheat because you used a larger size wire, the wire is not going to make the alternator put out more amps then it's made for, the terminal on the alternator is designed for the amps it can put out, the wire size has nothing to do with it. a larger wire has less resistence then a smaller wire,therefor it heats up less not more. these guys need to go back to school to lear basic electrical theory, everytime i hear someone tell people this BS it makes me want to start an electrical installers school or something. reminds me of the guy who said i couldn't install power door locks in my 86,because it didn't have the "computer" for them. what a load of shit.
 

Ali1

e6300 FTW
10+ year member
May 5, 2006
3,643
10
U.S.
i have nissan maxima 2000engine:VQ30DE

i need ~400 amp alternator for my car

what do you recommend me??

plz help me!
you'll be hardpressed to find someone who can even build a 400amp alternator for that particular vehicle....

what does your system consist of that draws this much amperes???

your best bet is to run a dual 250amp alternator setup with custom brackets... if thats even possible

 

1rockford1

Banned
5,000+ posts
Aug 8, 2008
13,456
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soon to be upstate ny
with a ho alt of at least 200 amps really puting out a max of 150 or so with the stock wires and zero big 3 i should have no issue with current flow from alt and battery and to my amp?

 

alfonsoleo

powered by memphis
10+ year member
Dec 6, 2008
25
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illinois
i have heard of people switching out the pully on the alt. to a smaller one. Would that work?

 

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