A car that refuses to start or lock can be a confusing and inconvenient situation for any driver. When facing these issues, understanding the potential causes behind such problems becomes important.
From electrical malfunctions to mechanical faults, various factors can contribute to a car’s failure to start or lock properly.
In this guide, I outline why your car won’t start or lock and the solutions.
Here’s why your car won’t start or lock:
1. You have a dead or weak battery
A dead or weak battery is a common reason why a car won’t start or lock and other electrical components do not function.
Car batteries are essential for providing the initial power required to start the engine. When a battery is weak or dead, it might not have enough remaining charge to power low-demand accessories like the dashboard displays, radio, door locks, or lights and also not enough power to crank the engine.
Signs of a dead or weak battery are:
- Dimming lights, that is when you attempt to start the car, the interior and exterior lights might appear noticeably dimmer than usual.
- Clicking sounds when turning the key in the ignition, you might hear rapid clicking noises, indicating that there is power, but it’s insufficient to engage the starter motor.
- Slow cranking or no cranking of the engine. The engine might crank slowly or not at all when you turn the key, signaling a lack of power to start the car.
- Electrical issues. Other electrical components might not function properly or show erratic behavior, such as power windows moving slower than usual or the horn sounding weak.
A dead or weak battery could be the result of various factors including, aging batteries which naturally lose their ability to hold a charge efficiently, drainage of the battery by leaving lights, interior accessories, or the radio on when the engine is off and faulty charging system due to issues with the alternator which charges the battery while the engine runs.
Therefore when the battery lacks the necessary power to engage the starter motor, the engine won’t crank, and you will have an unresponsive car.
To address a potential dead or weak battery, try jump-starting the car with jumper cables connected to another car or a portable battery booster.
If the car starts after a jump-start, have the battery and charging system checked by a professional to prevent future issues.
If the battery is old or consistently weak, replacing it is necessary to ensure reliable starts.
Related: Car won’t start parked downhill (Explained)
2. The starter motor is faulty
The starter motor is responsible for initiating the engine’s combustion cycle by turning the crankshaft, which starts the engine running.
When the starter is defective or worn out, it might prevent the engine from cranking and lack electrical power for accessories like the door locks.
Signs of a faulty starter are:
- No response when the key is turned
- Intermittent starting Issues where the car might occasionally start and then fail to start on subsequent attempts, indicating an inconsistent problem with the starter.
- A grinding noise when starting the engine which indicates worn-out gears in the starter motor.
- Smoke or burning smell due to a faulty starter or a burning smell due to electrical issues or internal damage.
A faulty starter might occur due to wear and tear over time of the starter motor’s internal components leading to malfunctions, electrical problems with the starter solenoid, wiring, or connections which cause starter failure and mechanical failure due to damage to gears, bearings, or the motor itself which can hinder the starter’s ability to engage the engine.
Therefore when the starter fails to engage or turns insufficiently, it cannot create the necessary movement to start the engine, or other electrical components like the door locks.
To address a potential faulty starter, a professional diagnosis by a mechanic is required. They can perform tests to determine if the starter motor is the culprit and replace it if necessary.
Ignoring starter issues can leave you stranded as the problem worsens, so prompt attention to starting problems is important.
3. The ignition switch has problems
Issues with the ignition switch can cause the car to not start while also not allowing other electrical components, such as the door locks, to function.
The ignition switch is responsible for initiating the car’s starting process by sending power to various systems, including the starter motor and fuel system.
When the ignition switch fails or malfunctions, it might prevent the engine from receiving the necessary power to start and also not allow power to other accessories.
Signs of ignition switch issues are:
- No response when the key is turned
- Intermittent starting problems
- Stalling while driving
- Difficulty turning the key
- Electrical malfunctions of other electrical components may behave erratically, such as flickering dashboard lights or non-functional power windows, due to problems with the ignition switch.
Ignition switch issues can arise due to wear and tear over time leading to connectivity problems, faulty wiring or connections related to the ignition switch which disrupt the flow of electricity, and mechanical or electrical failures within the switch itself can cause starting problems.
If you suspect an issue with the ignition switch, it’s important to have it inspected and repaired by a qualified mechanic.
Ignition switch problems can lead to unexpected stalling or complete starting failure, so addressing these issues promptly is essential for the safe and reliable operation of your car.
Related: Car won’t start gas smell (Here’s why)
4. Corroded battery terminals or connections
Corroded battery terminals or connections can impact a car’s starting ability and also not allowing other electrical components, like the door locks, to function.
When there’s corrosion or a poor connection at the battery terminals, it impedes the flow of electricity required to start the engine.
Enough power might not reach the door locks and other low-demand accessories because the high demand for power needed by the starter motor might be hindered by the corroded or loose connections.
Signs of corroded battery terminals or connections are:
- Difficulty starting
- Intermittent electrical Issues
- Visible corrosion
- Loose connections
Corroded battery terminals or connections can occur due to battery acid buildup, moisture exposure on the battery components, and lack of regular cleaning or maintenance of the battery terminals and connections.
To address issues related to corroded battery terminals or connections, it requires:
- Cleaning: Carefully clean the terminals and cable connections using a wire brush and a solution of baking soda and water or a specialized battery cleaning solution.
- Tightening connections: Ensure all connections are snugly fitted and tightened properly to the battery terminals.
- Preventive maintenance: Regularly inspect and clean the battery terminals to prevent future corrosion.
If the corrosion is severe or if the connections are significantly damaged, have a professional mechanic inspect and potentially replace the affected components to ensure reliable starting and proper electrical function in your car.
5. Fuel delivery problems
Fuel delivery problems can contribute to a situation where a car won’t start.
These issues involve the fuel system’s inability to deliver an adequate amount of fuel to the engine, resulting in starting difficulties.
Signs of fuel delivery problems include:
- The engine cranks but doesn’t start
- Sputtering or stalling
- A strong smell of fuel
- Difficulty starting when cold
Fuel delivery problems can arise due to a clogged fuel filter, faulty fuel pump, fuel line issues, and fuel injector problems.
When the engine lacks the necessary fuel to ignite the combustion process, it won’t start or may struggle to start.
While electrical systems like door locks can operate with the available battery power, lack of enough battery power or underlying problems can prevent lock function, coupled with insufficient fuel reaching the engine which prevents it from running.
To address potential fuel delivery issues:
- Check fuel levels: Ensure there’s an adequate amount of fuel in the tank.
- Inspect fuel lines and connections: Look for visible damage, leaks, or loose connections in the fuel lines.
- Replace fuel filter: If the fuel filter is clogged, replacing it can restore proper fuel flow.
- Test fuel pump and injectors: A mechanic can perform diagnostic tests to check the fuel pump’s pressure and the injectors’ functionality.
Given the intricacies of the fuel system, diagnosing and repairing fuel delivery issues might require expertise.
Consult a qualified mechanic for a comprehensive evaluation and resolution of fuel-related starting problems in your car.