as I was driving the lights started to dim and the radio went off and now the car stalled. It won't restart without a jump from another car.How do I tell the difference if the alternator or battery in my car is bad, the electrical system is failing?check the pulley belt .. if its loose tighten the belt and start the engine and put everything on .. lights heater wipers anything ...if you find its still dim and slow .. then alternator is no Good change it ... if everythings working ok then the battery is no goodHow do I tell the difference if the alternator or battery in my car is bad, the electrical system is failing?A bad battery is easy to test. Hook it up to a battery charger. If it's bad, it will only charge so far and then the needle will crash back to the begining or it will only go so far and stop. If the battery becomes fully charged, it's your alternator.How do I tell the difference if the alternator or battery in my car is bad, the electrical system is failing?get them tested. I take out the alternator and have it brought to autozone and have it tested and same for the battery. ur alternatoer could be bad and draining the batter there test they can do to see. i have to see the car to figure it out.How do I tell the difference if the alternator or battery in my car is bad, the electrical system is failing?SOUNDS like a bad alternator.How do I tell the difference if the alternator or battery in my car is bad, the electrical system is failing?First, ensure the battery connections are clean and tight.
This test is not 100% accurate, however I've never seen it fail.
The next time it's running, disconnect the positive cable.
If the car dies, you have been running off your battery - therefore have the alternator check.
If the car continues to run, the alternator is putting out current, however if may not be enough or the battery won't hold a charge.
Personally, I would take the battery to an auto parts store and have them check it. If it's okay, then take the alternator. Or take them both at the same time.How do I tell the difference if the alternator or battery in my car is bad, the electrical system is failing?Been there done that.Your alternator is bad.And you ran down your battery.How do I tell the difference if the alternator or battery in my car is bad, the electrical system is failing?Have the battery tested and replace if needed, but make sure the alternator is still ok. Sometimes when the alt goes bad it will take the battery out.How do I tell the difference if the alternator or battery in my car is bad, the electrical system is failing?all you have to do, is test the battery. hook it up to another battery, or just replace the alternator, which is cheap and easy, and probably what it is anyway.How do I tell the difference if the alternator or battery in my car is bad, the electrical system is failing?buy a new alternator and a battery, trust me my 99 alero did the same thing, don't listen to them.How do I tell the difference if the alternator or battery in my car is bad, the electrical system is failing?take the alternator and the battery to the parts house and have them checked and replaced if needed
