MAYH3M

iTrader: (12)

Well, I have the feeling my Alternator may take a **** soon, my volts are usually around 10 or less.

My Fans are constantly on, which uses a lot of power, same with my 8000k HID's. I want to buy an Alternator that can power everything just fine, without sacrificing quality.

I can get OEM Reman Alternators for around $100, but they're 102 Amp. I've been seeing 120, 130, 160 Amp Alternators on Ebay for an unusually low price.

Would it be wise to go with a Higher output alternator?

Thanks

MAYH3M

iTrader: (12)

Anyone?

LS6427

iTrader: (2)

OEM's should be fine. Why are your fans on all the time?

MAYH3M

iTrader: (12)

I had the car tuned so they turn on at 173 degrees.

LS6427

iTrader: (2)

They turn off then while your driving when the t-stat opens.

Hawking821

thats cool.. wish i set mine like that

MAYH3M

iTrader: (12)

I'm pretty sure they're constantly on, but that's not even the point, lol.

I just want to make sure that If I buy one of these High output Alternators, it wont die in a year. And also, If I went with a Brand name Remanufactured 102 Amp Alternator, will it be enough to power everything.

whytryz28

iTrader: (28)

Im running the stock alternator on my 176k car. And i have a 2 amps and a kicker.

MAYH3M

iTrader: (12)

Alright, That's exactly what I wanted to hear. Thanks!

dancrosoft

FYI - HIDs use less power than stock lights . I think less than half...

MAYH3M

iTrader: (12)

But everytime my HID's go on, my volts drop by about 1 or 2.

LS6427

iTrader: (2)

Earlier this year I put in a stock OEM on mine from PepBoys. $149.00, lifetime warranty.

Its perferct. I have a 427ci and a 1,000 watt amp with an under-drive pulley. Never drops below 14 no matter what. Not even at idle with the A/C blasting, stereo cranking, wipers on, rear defroster on, headlights on.....thats how I test it.

The reason I asked why the fans run all the time is: Because any time you're on the highway at a steady cruise speed....the fans should NEVER come on. Even if they're set at 173 to come on. But....what t-stat do you have? If have anything higher than a 160 t-stat, you're defeating the purpose of having the fans come on at 173 and all you're doing is wearing out your fans.


.

angel71rs

Get a multimeter and check the voltage at the alternator output and compare it to the battery + (neg probe should be at battery - for both checks). If there is more than a fraction of a volt difference, you have bad continuity somewhere. If voltages are close, your charging system is weak.

Check all your wiring, including grounds. If everything looks good, pull the alt, have it tested for free at AutoZone.

1 FMF

iTrader: (1)

first keyword is "unusually low price"
second keyword is "ebay"

alternators are simple devices. The output you get, in terms of current at a certain voltage, is based on the size of the alternator and how fast it spins. For your car/engine, you are restricted to a certain size/model of alternator, otherwise you won't be able to bolt it in or hook the belt up to it. Given that, the more an alternator can output (in terms of current) the more heat it will generate. The first problem with high-output alternators is they are different guts inside the same casing which can only provide so much cooling to begin with, and most would argue the oem designed the alternator around this fact so it would be reliable. Second, output of the alternator is dependent primarily on rpm, and there's two parts to this- consider what rpm your engine normally lives at most of the time, usually idle to 2000 rpm. The slower the alternator spins the less cooling it gets via the fan on it's pulley, so that's problem 1; the other problem is output is dependent on rpm.
What you're not told about a high-output alternator is at what rpm it is capable of outputting the necessary amount of power you need. It is called a high-output, not higher power, and what they do is rate the output in amps which is deceiving! Most of the time the alternator only outputs greater amperage at higher rpm which is usually more power but the higher rpm makes it irrelevant. The other deception, still related to power, is they trade off voltage for more amperage, so while at a low rpm they may claim the alternator is capable of producing more amps there is less voltage. If you have a voltage lower than 13 volts then you are still discharging your battery, and have dim lights and things don't work. This is what usually happens. The real solution is to do a pulley change on the alternator to a smaller pulley so it spins faster at lower rpm, or simply run the engine faster- it's all simple physics, to get energy out you have to put energy in somehow, and it is done mechanically by the speed of which the alternator spins... for the most part. Otherwise it's the general size of the alternator- how strong the magnetic field is and the amount of windings on the rotor and stator. Again, because it's the same physically sized alternator, more than likely it's not going to output more power in the lower rpm range.

Now i'm not saying all "high output" alternators are bad or falsely advertised. But given that these high output alternators are (a) on ebay and (b) priced unusually low, do not buy them. The real high-output alternators will first cost you more money, usually > $300, and they will or should be bigger.
So unless you want to fork out cash for a a real high-output alternator, stick with the oem alternator that's a name brand from a reputable part store- napa, advanced auto, autozone, etc. and get one with a free lifetime replacement warranty.

smaller alternator pulley:
http://www.alternatorparts.com/pulley_size.htm


http://www.alternatorparts.com/FAQ.htm
http://www.alternatorparts.com/under...lternators.htm
http://auto.howstuffworks.com/alternator1.htm

MAYH3M

iTrader: (12)

That was a great post! Thanks for the heads up