How To Check If An Alternator Is Bad?
One of the most important components of your engine is the alternator. An alternator recharges your vehicle’s battery when you are driving on the road and is frequently found attached to the front of the engine block. Without an alternator, your battery can quickly lose power and you can be stranded. To avoid a costly breakdown or early warning signs of failure of your vehicle’s alternator by being aware of how to test an alternator in your vehicle.
Things To Consider Before Testing An Alternator
You will initially require the following things in your hand: safety glasses, a three-foot rubber hose, a voltage meter or a digital multimeter, and road chocks.
Performing Alternator Voltmeter Test
Step 1. Park Your Vehicle On A Level Ground
Park your vehicle on a level surface, turn off your vehicle engine, and put the wheel chocks around the rear tire on the driver's side.
Step 2. Open The Hood Of Your Vehicle
To find the alternator in your vehicle safely open the hood of your vehicle.
Step 3. Locate Your Vehicle’s Alternator
The alternator is found close to the front, top of the engine. But in some automobiles, it might be near the bottom of the engine.
Step 4. Check Your Vehicle’s Engine Drive Belt
Check your vehicle’s engine drive belt for tightness by applying pressure to the engine drive belt between any two pulleys. The alternator may not charge properly if the engine drive belt is loose.
Step 5. Hear The Noises Coming From Your Vehicle
Start your vehicle’s engine and hear any strange noises such as squeaking or grinding.
Step 6. Check Your Vehicle’s Alternator Bearings
Attach a rubber hose on one end of the alternator casing and the other next to your ear. The alternator bearing has to be replaced if the grinding or squeaking is quite loud when you listen through the hose.
Step 7. Connect The Voltmeter To The Battery
Turn off your vehicle’s engine. Place the positive lead on the positive (+) terminal of the battery and the negative lead on the negative terminal of the battery with your voltage meter turned on and set to DC volts.
Step 8. Observe The Voltage On The Voltmeter
Observe the voltage on the voltmeter. It should read between 12.5-12.65 volts. If it's lower than the range then you should conduct a load test on the battery. Again start your vehicle’s engine, then check the voltage reading on the voltmeter. The voltage should be at least 13 volts. The voltage output of a good alternator should range from 13.5 to 14.5 volts.
Step 9. Test The Alternator With More Stress
To put more stress on the alternator, you can turn on the headlights, the radio, and the air conditioning system of your vehicle. When these systems are switched on the voltage on the voltmeter should be high. If the voltage on the voltmeter does not change or it does not get above 13 volts then your vehicle’s alternator is not working properly and needs to be replaced. If the voltage on the voltmeter is low, you can lightly move back and forth the electrical connections on the back of the alternator to see if the voltage changes. If it does then there will be loose or corroded connections on the alternator or the battery that causes bad alternator readings.
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