Alternator Brush

How To Check Alternator Brushes

Alternator brushes provide power directly to the field coil through slip rings. These graphite brushes are designed to last more than 120,000 miles. If these brushes are worn, the battery in a car or truck may not charge or the battery warning light may remain illuminated after the engine starts. Although brushes may be marked with a wear limit, maintenance experts recommend replacement once these components become half worn. AutoZone sells the best alternator brushes for cars and trucks by Duralast.

The best way to determine whether you may need to replace brushes is to use a voltmeter to check voltage. If the meter reads under 13 volts when the engine is idling without electrical equipment powered on, below 12 volts when this equipment is on or the reading remains low as engine rotations per minute increase, brushes may require replacement.

Replacing Alternator Brushes

It is necessary to disconnect the battery and remove the alternator to switch out brushes. Alternator brushes are usually located near the rear of the alternator. Depending on the design, you may need to remove a molded end cover, loosen the retaining screws for brush terminal strips or lift out the brush box. It may be possible to remove the brush holder from the outside.

Slip rings are less likely to wear out than brushes, but the brush replacement process is an ideal time to clean these components. You should also clean the housing and guides for alternator brushes. Methylated spirit is a useful cleaning solution for all of these parts. Make sure that the new brushes fit into the holders and use a file to rub down any protruding parts. Brushes and springs must be the correct size to provide a precise, vehicle specific fit.

Competitive Alternator Parts Prices

AutoZone has the lowest prices on alternator brushes as well as other alternator and charging system parts. Whether you are looking for a replacement alternator or bearings, bushings, diodes, pulleys, resistors or spacers, we make it easy to find the right parts for your car or truck. Enter the year, make, model and engine type of your vehicle to increase the likelihood that the parts you see when searching or browsing our site should provide the right fit.

In Store Pickup and Delivery

We make it easy to get any parts you need. Searching for alternator brushes near me can show you what is currently in stock at the closest AutoZone store location. If you are looking for a component that is not in stock, it may be possible to order for in store pick up or home delivery as soon as the next day. These customer-friendly options make it easier to complete alternator repairs and get back on the road.