How to Fix a Slow Cranking Starter

A slow-cranking starter can be a nuisance and cause major headaches if not fixed in a timely manner. It can lead to longer start times and even complete failure of the car’s ignition system. Knowing to fix a slow cranking starter can help you save money on costly repairs and ensure your vehicle is running in top condition.

How to Fix a Slow Cranking Starter

A starter motor can crank the engine with relative ease when working properly. However, when the cranking speed starts to slow down, this usually indicates that something is wrong and needs to be fixed. Fixing a slow cranking starter can help prevent further damage or even total breakdown of the entire system. In this blog post, we will cover the basics of how to fix a slow cranking starter so that you can pick the best option.

Step by Step Processes for How to Fix a Slow Cranking Starter

Step 1: Inspect the Battery

It’s important to check the battery if you are having issues with slow cranking. A weak or dead battery can cause a slow start and should be replaced if needed. The starter motor solenoid is responsible for activating the starter motor when the key is turned in the ignition, so if this fails, it can cause your engine to crank slowly. The solenoid can be tested with a test light or multimeter and should be replaced if faulty.

Step 2: Check the Alternator

The alternator is responsible for keeping your battery charged. If it is not functioning properly, this will cause a slow cranking starter. Use a test light or multimeter to see if the alternator has continuity between its terminals and check for any signs of damage. If needed, replace the alternator to resolve the issue.

Step 3: Inspect the Starter Motor

Starter Motor is Responsible

The starter motor is responsible for cranking the engine. If it is damaged or failing, it can cause a slow start. Inspect the starter motor for damage and check that its solenoid is functioning correctly. Replace the starter if needed. The wiring that leads to the starter motor can become damaged or corroded over time. This will cause a slow start and should be inspected and replaced if needed.

Step 4: Check the Starter Relay

The starter relay sends power to the starter motor when the key is turned in the ignition. If this fails, it can cause a slow start. Inspect the relay and replace it if needed. The ground connection should be checked, which can cause a slow start. Ensure that all the wirings are securely connected to their corresponding terminal on the starter motor, battery posts, and any other connection points.

Step 5: Replace the Spark Plugs and Wires

Spark plugs and wires become worn over time and can cause a slow start. Inspect these components for any signs of wear or damage, and replace them if needed. The ignition coil is responsible for providing a spark to the spark plugs. If it is faulty or damaged, it can cause a slow start. Check for any signs of damage and replace them if needed.

Step 6: Inspect the Starter Solenoid

The starter solenoid activates the starter motor when the key is turned in the ignition. If this fails, it can cause a slow start. The solenoid should be tested with a test light or multimeter and replaced if faulty. Corroded battery terminals can cause a slow start, so make sure to clean them regularly with baking soda and water. This will help prevent any buildup of corrosion and ensure a strong connection between the terminals and battery posts.

Tips for How to Fix a Slow Cranking Starter

  1. Always wear protective eyewear, gloves, and clothing when working on a slow-cranking starter.
  2. Be sure the vehicle is parked in a safe area before beginning work on the starter motor.
  3. Disconnect the negative battery cable to prevent the risk of electrical shock or shorting out circuits while working on the starter.
  4. Use a socket wrench and appropriate sizes sockets to remove bolts on the starter motor housing.
  5. Inspect all of the components within the starter, including wiring connections, solenoid connections, and brushes, for signs of wear or corrosion.
  6. Clean any visible corrosion on terminals or wires with a wire brush and baking soda.
  7. Replace the starter motor if it is damaged or not functioning correctly.
  8. Test the connections after the new starter is installed to ensure it turns over quickly and properly.
Replace the Starter Motor

By following these safety tips, you can safely and successfully perform the necessary repairs on Fixing a Slow Cranking Starter. It will also ensure that your vehicle continues to operate smoothly and efficiently.

How Clean Are the Battery Terminals and Connections?

  • Disconnect the negative battery cable from the battery’s negative terminal and clean both terminals with a wire brush or baking soda/water mixture.
  • Ensure that all connections are secure and free of corrosion or rust. If necessary, tighten them or replace them entirely.
  • Reconnect the negative battery cable to the negative terminal and check to see if there is a spark when reconnecting it. If not, check the tightness of the terminals again or replace them entirely.
  • Clean all other connections related to the starter motor, like battery cables, ignition switch, and solenoid, with a baking soda/water mixture or a wire brush.
  • Check for any loose connections and tighten them if necessary. If the problem persists, consider replacing them entirely.
  • Test to ensure all connections are properly secure before reconnecting the battery cable to the battery’s negative terminal.

By following these steps, you should be able to fix a slow cranking starter. If the problem still persists, it may be due to a faulty battery or starter motor, so consider replacing them if necessary.

Are Any of the Critical Components (Solenoid, Solenoid Switch, Ignition Switch) Defective or Malfunctioning?

A slow cranking starter is often due to defective or malfunctioning critical components. Checking to see if any of these components (solenoid, solenoid switch, ignition switch) are in need of repair or replacement can help you diagnose the problem and take the necessary steps to fix it. If any of these parts are found to be defective, you will need to replace them.

Checking for Voltage Drop

You will need to test each one individually to check for any defects or malfunctions in these components. This can be done by connecting a voltmeter to the starter solenoid and checking for voltage drop when the key is engaged. The starter solenoid may be faulty if too much voltage is lost during the process.

Similarly, you can check the ignition and solenoid switch by connecting a voltmeter to each one and measuring the voltage drop when the key is engaged. If any of these components are found to have excessive voltage loss, they should be replaced as soon as possible to fix your slow-cranking starter.

How Much Corrosion is Present in the Spark Plug Wells and on the Spark Plugs Themselves?

To start, you will want to inspect the spark plug wells, and the spark plugs themselves for any signs of corrosion or dirt. If there is a buildup of dirt or corrosion on the spark plugs, it can act as an insulator, preventing electricity from flowing properly and leading to a slow cranking starter.

To clean these parts, you can use a wire brush to scrub the spark plug wells and an old toothbrush to clean off the plugs. If there is severe corrosion or dirt, you may need to replace these parts with new ones. Once everything is cleaned up, attempt to start your vehicle again. If it still does not start as quickly as before, continue on with the other steps listed here.

How Much Will It Cost to Fix a Slow-Cranking Starter?

The cost to fix a slow cranking starter can vary depending on the cause of the problem. The repair may be relatively minor and inexpensive if the issue is due to a faulty battery or corroded connections. A new battery may cost $50-$100, and cleaning up corroded terminals will likely only require some supplies from your local auto store.

If the problem is due to a worn or damaged starter, then it could be more expensive to repair. Parts and labor costs for replacing a starter can run $100-$400 depending on the make, model and year of your car.

If the issue is complex and requires further repairs, such as replacing other parts connected to the starter, the cost will be higher. It’s always best to consult a professional mechanic for an accurate cost estimate before beginning any repairs.

Consult a Professional Mechanic


The main disadvantage of fixing a slow-cranking starter is the cost of replacing parts. For example, replacing the starter motor or battery can be relatively expensive. In addition, even if these components are replaced, there is no guarantee that the problem will not return in the future. Finally, not all vehicles have easy access to their starter motor, making diagnosing and fixing the problem difficult.

In conclusion, fixing a slow-cranking starter can be an intimidating task. However, it is possible to fix a slow-cranking starter with the right information and tools. In most cases, this involves inspecting the battery cables for corrosion or damage and cleaning them as needed.

The starter motor should then be checked for power and ground connections, wiring continuity, solenoid engagement, and torque. If the starter motor needs to be replaced, it is best to do so with a manufacturer-approved model. I hope this article has been beneficial for learning how to fix a slow cranking starter. Make Sure the precautionary measures are followed chronologically. 

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