Whether your alternator malfunctions, it won't properly recharge your battery. Connect the negative "black" voltmeter cable to the negative battery terminal.5. Start the engine and check the voltmeter. They besides wear away and own to be replaced.
Instructions
1. Sincere the hood. Fix the battery, the alternator and the alternator belt.
2. Inspect the battery terminals and cables. A loose connection or corrosion around the terminals will prevent the alternator from recharging the battery. If the battery terminals are corroded, you will see a whitish-green, powder-like substance. Clean the terminals with a wire brush. Tighten the cables' connections with the terminals with a screwdriver and tighten loose terminals with a wrench.
3. Press down on the alternator belt with your index finger. If the belt gives more than half an inch, it is too loose and should be tightened. Visually inspect the belt. If it's cracked and worn, it should be replaced.
4. Connect the positive "red" voltmeter cable to the positive battery terminal. At some location, you'll be stranded with a dead battery. A poor alternator displays symptoms such as dim headlights, a slow cranking engine, and diminished electrical accessories. Squealing noises from under the hood present a loose alternator region. Alternators and alternator belts thirst for maintainance.
It should read between13.8 and14.2 volts with no lights or electrical accessories turned on.
6. Turn on the lights and electrical accessories and check the voltmeter again. If it is reading less than 14.2 volts, the alternator is undercharging the battery. This indicates bad diodes. If it reads higher than 14.8, the alternator is overcharging the battery. This indicates that the alternator's regulator is malfunctioning.
