If the car’s starter motor clicks and the engine won’t turn, this could be due to a number of things. The most common cause of clicking when the car is started is a low battery. Most people would assume the starter is bad if it just clicks, but low voltage can cause the starter to make this sound.
The battery is the heart of the electrical and starting system. If the battery is dead or has a weak cell, this can cause the starter to click only. Many times, the battery can be drained from a door being left slightly open, causing the overhead light to stay on. Other times, a vanity light or phone charger can be left on. During my time as a skilled automotive technician, a trusted coworker locked me in the trunk to make sure the trunk light went off when the trunk was closed.
To test the battery it must have a good charge. If the battery is not fully charged, the tester will indicate that it needs to be charged before the test can continue. The first step in checking the starting and electrical system is to make sure the battery is in good condition. Most auto parts stores check batteries for free. Once the battery is determined to be good, the rest of the system can be verified. Loose or corroded connections can also cause a click and the car won’t start.
Beginning
The starter solenoid on many Ford vehicles is on the inner fender, on most other vehicles the starter solenoid will be mounted on the starter motor. The click you hear many times is the solenoid. But low voltage from a dead battery, a bad battery, or bad connections can cause this. Most of the time, if the vehicle can be started, the starter is fine. This would also indicate that the connections to the starter are good.
Alternator
Once the vehicle is running, the alternator output can be checked. If the alternator does not charge the battery, it will drain during the process of starting and driving the car. When the alternator is checked, the voltage and amperage output can be measured. Also, the diode pattern will be checked to ensure that the alternator does not drain the battery when the engine is off. In the past, DIYers could disconnect the battery while the vehicle is running to check the alternator, if the car was still running the alternator was fine. Doing this on computerized vehicles can be detrimental. If the battery is disconnected while a computerized vehicle is running, the alternator output can increase dramatically, allowing excess voltage to boost the computer.
Battery
When purchasing a replacement battery, the cold cranking amps required for the vehicle should be checked. Better to buy a battery with more cold cranking amps than the minimum required. Also, when buying a battery, you need to consider whether you want it to be maintenance-free or not. If the battery is difficult to access or has a cover, a maintenance-free battery is preferred. For example, on some Chrysler Sebrings and Chevrolet Corvettes, the battery is located behind an interior fender and on a Chevrolet SSR. The battery is located under the bed where the spare tire would normally go. If you install the battery yourself, be sure to note which side is positive and negative in case you have been sold the wrong battery.
Terminals
Terminals must be free of corrosion and must be tightened securely. Sometimes, especially on import vehicles, the battery terminals will be very thin and may have small cracks causing a poor connection. Avoid forcing the battery terminals by touching them. The battery case can be damaged and cause a leak; If battery acid leaks out, it can cause rapid corrosion. If the battery terminal bolts are not tightened, it is recommended to replace the terminals. When the connections are tight, you shouldn’t be able to twist them by hand.