Can a car run with a bad Alternator? Maybe, but it would be for a very short time. What the Alternator does is it charges the Battery. Once the energy in the Battery is gone, the car will die or won’t start at all. Symptoms of a bad Alternator: 
- Your lights are dim or overly bright. As your Alternator starts to fail the voltage to the Battery is very inconsistent.
- Dead Battery. Yes, sometimes the battery is just dead, the life of a Battery is about 4-6 years. If the Alternator is bad it intermittently will charge the Battery.
- If the Alternator is going out the Vehicles’ electronics will be slow or won’t work.
- If you notice you have trouble starting the car or it stalls frequently the Alternator is not charging the Battery. Turning the key to start the car you may hear a clicking sound instead of the Engine starting.
- Noises at times maybe hard to pin point the problem unless our Mechanic can fully check it out. A growling or whining noise could be bad Alternator, but could also be belts or bearings. So bring your Vehicle to the Experts.
- Last but definitely not least is the Battery Warning Light goes on. It’s not always the Battery it can be a problem with the Electrical System which could be the Alternator.
