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Are you looking to swap out your in stock alternator? Well, there are many good reasons to make the shift to a high-output alternator, but still you need to do some homework regarding the same. Fortunately, this webcast can help you with using the high output alternator so that you can just ace the topic. Therefore, we have come up with five things you need to know before upgrading to a high output alternator. Let’s start with some of the basic questions!

Do you really require a High-Output Alternator?

If you have got a basic, stock vehicle, possibilities are you don’t require a high-output alternator. Majority of factory alternators are rated at 65 to 100 amps and are well capable of managing your vehicle’s basic necessities, such as the headlights, gauges, fuel pumps, A/C. etc. All these alternators usually come with 10-15% reserve to take care of the additional accessories.

For instance, you may have a custom-built street rod with a unique combination of accessories. Or you might have a high-end stereo system or a race vehicle with an array of on-board electronics. Since the electrical load of all these accessories get add up, you might find yourself in need of a high output alternator.

But will you come to know?

Well, there are a couple of ways to find out whether you need to upgrade your alternator. A few telltale signs include the dim headlights, poor stereo system performance, or an alternator that just wears out quickly. Also you can check your electrical load using an ammeter. You just have to simply connect the ammeter in series with the battery’s ground terminal, switch each of the electrical components on and off, and gauge their current drawn. Then, add up the total electrical draw and compare with your alternator’s rates output. The output should be 50 percent greater than the amperage drawn.

And one final way to estimate your vehicle’s electrical load is to check the accessory fuses. The amp ratings, though slightly higher than the highest draw of each component, will provide you a good estimate of your vehicle’s electrical load.

What Amperage do you require?

That completely depends on the current drawn, together with future accessories you are planning to add. And for that very reason, we have come up with a list of some common accessories and their amp draw:


                               Accessory                           Amp Draw
Air Conditioner20-21
Audio Power Amplifiers10-70
Back-up Lamps3-4
Cigarette Lighter10-12
Dome Light1-2
Instrument Panel0.7-1.5
Lamp, Gauges1.5-3.5

Remember, you can never have too much amperage when we talk about alternators; therefore, you never have to worry about choosing an alternator with too high of a rated output. This is because amperage is basically the amount of electrical current your alternator can supply. And it basically functions off of supply and demand. Therefore, your alternator will only supply the amount of amperage a particular component demands, and nothing more. Hence, high-output alternators will not harm your components or the charging system, irrespective of how high you go with the amperes.

The Gauge Wire you need

A performance alternator really does not require much when we talk about the modifications. However, other alternator manufacturers do recommend you to replace both the ground straps and the charge wire. Just keep in mind that the factory cables were not designed to handle the juice of a high-output alternator, and can eventually restrict the flow of electricity. However, in case of charge wire, you really cannot go too large.

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