Rapid Clicking Sound When Starter is Used

A common problem with a car battery is low voltage. As a battery ages it loses the ability to store electricity resulting in an insufficient flow of electrical energy to the starter. Most starters are designed to operate on a high amperage 12 volt system. When a starter is subjected to low voltage or amperage (flow) it will cause the starter to engage and disengage rapidly producing the machine gun like sound. To fix this problem a battery inspection or replacement is needed. There are two reasons that a battery will not perform as it should, either the alternator has failed allowing the battery's state of charge to become weak or the battery has failed and replacement is required. 

Unfortunately to check the alternator the engine must be running, so you must either jump start your car or replace the battery to check the charging system. If the alternator output test is ok then the battery is bad and must be replaced. If while driving the charge light indicator on the dash was not illuminated and the battery is more than three years old the battery has probably failed.

Car Battery
Car Battery

Related Inspections

Check Battery Cable Corrosion - The battery cables are used to transfer electrical power from the battery to the starter. Battery acid causes corrosion inside the battery cable and will inhibit electrical flow. To check for this condition look for bulges near the top of the cable, these bulges indicate corrosion expansion caused by the chemical reaction between the acid and copper wire. Remove the failed battery cable to replace with new unit, then check charging system to ensure proper operation.

Inspect Battery for Bulging - The battery supplies electrical power to the vehicle, when a battery short circuits internally it can cause the car to lose power and gain it back again. Inspect the battery; if the sides are bulging it could have a warped plate that can short under certain conditions. To check for this condition the battery needs to be disassembled which is very difficult, and should not be attempted. This problem is rare but it does happen.

WARNING! Always wear protective eyewear, gloves and necessary clothing before inspection or work begins. Never crank an engine over when you are near the battery or engine. A battery is filled with acid that produce explosive vapors that can ignite when extreme heat or a spark is present. A battery could have residual acid on the outside casing so use caution when handling a battery and the surrounding area. Use baking soda to neutralize any suspected acid residue before work begins.

If further assistance is needed, our certified car repair technicians are ready to answer your car questions.

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Written by
Co-Founder and CEO of
35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


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Article first published (Updated 2014-03-01)