Should I Upgrade my Alternator?
Most alternators for passenger vehicles are rated between 60 and 200 amps, but you can install aftermarket units that generate up to 400 amps of current. Accessories that require more power include aftermarket stereo systems, snowplows, winches, industrial radios, and power inverters, so if you intend to install and use components like these on your vehicle you may want to consider an alternator with a higher amp rating.
The voltage will stay the same and you won’t damage your system by having a more powerful alternator. If you decide to upgrade your alternator, you’ll need to ensure that all the cables have enough thickness to handle the increase in current. If they are too thin, they could overheat when they’re under load and cause electrical faults or even a fire.
Factors that Indicate a High-Quality Alternator
When buying parts for your car, you want to make sure that they’ll have the quality and workmanship to last for the long haul. How do you determine the quality of an alternator? Your first clue should be the type of warranty that the alternator carries. If an alternator comes with a limited lifetime warranty, it indicates that the manufacturer has done its homework and completed quality testing on the unit so that it meets a set of requirements for lifespan. If the manufacturer provides testing information, you should check to see if the individual components of the alternator were tested before assembly and then the completed alternator was tested at the end of assembly. This indicates that the parts and the whole unit all function as intended.
The two items on your alternator that will tend to wear out the quickest will be the brushes and the bearings. It’s impossible to see the brushes, unless you open the housing of the alternator to look inside, but you can check the bearings without any tools. Just hold the alternator with one hand while spinning the pulley with the other. That will indicate how freely the bearings are spinning. A new alternator should have very smooth bearings. The other test is to try to move the pulley in, out and side to side to determine how tight the bearings are. If there is any play in the bearings, then the alternator is doomed to fail early.