How to Troubleshoot Car Alternators
Car alternators are one of the many repairs that you may need to make during the life of your car. If you begin to notice issues like difficulty starting your vehicle or your clock turning off once you power on your radio, it may be a sign that your alternator is failing. Addressing this issue in a prompt manner can keep you from costly expenses.
What You'll Need:
- Voltage - Ohmmeter
- Disconnect the battery while the car is still running. If the car alternator is functioning properly, the car should continue to run after the battery has been disconnected. If the car shuts off immediately or stalls, that is a sign that there is trouble with the alternator.
- Visit your local automotive part store and purchase a volt-ohmmeter (VOM). Generally, this piece should cost you less than $20.
- Check all the fuses that are connected or related to the alternator. Even if they appear to be in good shape, the VOM can verify their integrity. Pull each fuse and hook it up to the tester. The fuse is functioning properly when it reads zero. Next, check the wires connected and related to the alternator. Each of those should receive a zero output as well.
- Test the alternator by connecting the ground wire to the negative terminal of the battery and the other wire output of the alternator to the VOM. If it is functioning correctly you should receive an output between 13.8 and 14.2. If your reading is not within this range, you may need to consider replacing the alternator completely.
- Turn the car on and open up the hood. If you hear the alternator making any noises, that may be a sign of an issue that needs to be further researched. In some instances, this may be a signal of a problem with the belt. If so, you will easily be able to hear the sounds that are coming from the belt that is attached to the alternator. After replacing the belt the alternator should operate correctly.