How-To self check A Car Alternator and Battery without amp device
The two things that need to be said right out is the the battery is used to start the car. The Cars alternator is used to continue running the car after its started. The alternator also recharges the battery after it starts the car to keep it full for future starts.
How To self test your alternator
So you come out side and your car wont start it`s either totally dead or just slightly cranking. You don`t know what the problem is right? Maybe it`s the battery or maybe it`s the alternator not charging the battery properly after each start.
The picture below is a car battery terminal being removed using and open end wrench
Here is Free how-to information on self testing an alternator.
1) If the car wont start you need to get it running  first, give it a boost or a jump using jumper cables and a car, or the best thing to have is a Booster box it`s portable and hand held.
2) once the car is started you need to remove the p0ositive cable on the battery while the car is running. If the car shuts down your Alternator is in need of a change. If the car runs for five minutes while the positive cable is off the the battery is Dead and needs changing.
Safety tips Please read
Positive is usually the red cable but sometime maybe black if someone rigged their own homemade cable, so always find the mark on the battery look for the + symbol that is positive.
Always try to use short open end wrenches some take 10 mm others 1/2 inch the point is not to let both ends of the wrench touch positive an negative at the same time. This will cause a big spark and can blow the battery.
