Can You Test An Alternator With A Dead Battery. Then they go to test the battery with a battery tester device and see the battery is dead. The positive connection is red while the negative connection is black.
The positive connection is red while the negative connection is black. A fresh battery and a malfunctioning alternator however will quickly leave you stranded again. Turn the ignition key.
We give you step-by-step instructions.
Test the battery again while the engine is running. Some may recommend running the engine with the negative battery cable disconnected to test the alternator. This easy-to-use tester can test the aging and resistance of your battery and help you figure out whether you have an alternator or a battery problem on your hands. If the alternator is functioning correctly its likely that your dead battery was caused by a computer module that isnt shutting down when you turn off the car.
