Mistakes to Avoid When Buying a Car Alternator

For those looking to upgrade their vehicle and achieve better performance, an alternator is a smart place to start. This ingenious device acts as an internal generator, transferring the mechanical action of the rotating axles into energy through an electromagnetic generator, and is the reason car batteries last so long and can recharge themselves. Whether you’re looking to install a new sound system, LED lights, or just want better performance from your vehicle, it’s critical to keep the alternator in mind when doing any kind of car repairs or upgrades.

However, there are some basic mistakes that the average person can make when going to purchase a car alternator. The last thing you want to do is cost yourself extra money, waste time, or expend effort on something, only to have it not live up to the performance and expectations you deserve. Let’s take a look at the most common mistakes people make when buying alternators, and how to avoid them.

1. Buying a used or refurbished alternator

While buying a used alternator can save you money initially, it’s often not the best idea, especially without a guarantee or warranty. Buying a used alternator means that you are installing a piece of unknown quality into your vehicle. You really don’t know how far along it is in its lifespan or what kind of stresses it has been under in its life.

In addition, buying used, especially without a complete understanding of the requirements, can mean that you end up with an alternator that doesn’t quite fit your vehicle. The pulley has to be the right size and shape for your vehicle, the mounting brackets must fit, and the wiring must be able to connect without pulling or stretching too far. If you choose to go this route, always keep the receipt, but a refund is never guaranteed and for a little more money you can get a new alternator that will be more reliable, perform better, and last longer.

2. Not addressing the original cause of failure

If you are experiencing issues like dim lighting, frequent dead batteries, trouble starting, equipment like the radio or AC not working, or strange noises from under the hood, it’s likely time to install a new alternator. However, there’s a common mistake that many people make when it comes to automotive repairs, which is neglecting to fix the root cause of the issue, which can lead to repeat failures and wasted time and money.

Addressing the root cause of your alternator issue can take some time, equipment, and experience. You’ll want to use a multimeter or oscilloscope to diagnose any electrical issues that could be coming from the engine, as well as other common points of failure like the wiring, grounds, and other points of connection to the engine. Simply replacing the alternator without diagnosing what caused it to fail can lead to another failed alternator shortly afterward, so always make sure you understand why the original failed first.

3. Buying an alternator that is too weak

Often, when people choose to upgrade their alternators, it’s because they have a specific performance upgrade in mind. This might be to install a loud subwoofer system that draws more power than standard speakers, customized lighting like LED strips, or even something like hydraulic lift systems. In addition, if you are upgrading your vehicle to go faster or for racing, you’ll want a performance alternator to handle the increased power that is being sent through it.

A common mistake that is easy to make is buying an alternator that can’t handle the loads you will be drawing from it, which can lead to a quickly burned-out alternator. Classic cars and older vehicles often have less sophisticated alternators, and if you’re upgrading the lights or adding AC and a stereo to an older vehicle, you’ll need to upgrade the alternator from what it was issued with to something more powerful. Always be sure to calculate the amount of amperage you will need to properly power your vehicle and any modifications you added.

In addition, it’s a good idea to upgrade the ground straps and the power cable that runs from the battery to the alternator to thicker and more robust gauges if you are upgrading the alternator. This will help it last longer and prevent wear and tear. It’s a good idea to choose the thickest gauge that will work in your vehicle when making these upgrades.

Alternators are an often overlooked piece of equipment when it comes to cars, but one that we couldn’t do without. It’s critical to keep our battery charged, start the car, and keep things like the headlights working properly. If you’re looking to replace or upgrade your alternator, keep these tips in mind and you will be well on your way to choosing the right alternator.