Alternator Repair in Manassas, VA

Alternator Repair, Testing, and Replacement for All Makes and Models.

Alternator problems are fairly common – most people will probably have trouble with the alternator during their car’s lifetime. And since the charging system is a crucial part of your electrical system, it’s important that you know a little bit about it.Alternator


What is an Alternator?

An alternator’s primary purpose is to maintain the battery. It is an A/C generator that’s responsible for keeping your battery charged and supplying power to operate lights and other electric accessories when your car is running (cars and trucks used to have DC generators, but manufacturers switched to alternators because they charge better at low RPMs). Your vehicle’s engine runs the alternator via the engine drive belt, aka the serpentine belt.


Symptoms of a Bad Alternator

A faulty or failing alternator can cause major electrical problems and can be difficult to diagnose. For instance, a battery problem often seems like an alternator problem and vice versa. Therefore, we recommend bringing your car, truck, van or SUV to Coho Auto if experience any of these symptoms:


  • “Batt,” “Alt,” “Gen” or the battery symbol light appears on the dash
  • Headlights start going dim
  • Gauges flicker
  • Squealing sound coming from the engine
  • Slow starting
  • Not starting


Any one of these might not necessarily mean that your alternator needs to be replaced, but it does mean your electrical system needs to be, at the very least, inspected by a knowledgeable professional. It should also be noted that you could have an alternator problem WITHOUT a warning light appearing in the dash. The alternator is responsible for turning this light on and off and if it’s bad, the light might not turn on. Therefore, your car would still start and run normally until the battery was completely drained.


Testing and Replacing an Alternator

Testing an alternator used to be a lot easier and safer than it is today. With the number of sophisticated computers and components found on late model vehicles, diagnosing an alternator problem can be dangerous and costly, especially if you accidentally short out the electrical system. And while this auto repair might appear on its face to be relatively simple, it is more complicated than just disconnecting the battery, removing the serpentine belt, and unbolting the alternator. The connecting wires, electrical plugs, mounting brackets and serpentine belt all need to be thoroughly inspected and reinstalled correctly.


Troubleshooting and repairing an alternator problem on either a domestic or foreign vehicles requires having the latest computer equipment, software, and diagnostic tools. And if you want the job done the right way, the first time, it also means finding a knowledgeable and experienced shop – like Coho Auto.

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