Symptoms of a Bad Starter Relay and How to Troubleshoot?

It is one of the most forgotten parts of any vehicle. Exactly, we are talking about the starter relay. This component is designed for a specific purpose, and just like the rest of the parts, it can fail from time to time. 

Find out the most common symptoms of a bad starter relay and we’ll show you how to fix it correctly.

What Is The Purpose Of This Component?

The starter relay is an ignition system that sends the power from the vehicle’s battery right to the starter solenoid. In other words, it is a switch that is placed between the starter motor and the component named solenoid.

Its main goal is to transmit current from the car’s battery for it to start correctly. Many people can confuse a starter relay with a different component named starter solenoid. They are different from each other but they can work together. 

A solenoid has to become the coil of a connector, which carries the electrical current from the first solenoid and to the starter motor. Also, they are designed to engage the starter pinion with the help of ring gear on the engine. 

Whenever a driver inserts the key into the ignition hole to turn it on, the relay receives power, which has to transfer it to the starter solenoid, which later transmits it to the starter motor. 

Then, the relay has to send electricity in small quantities to the starter solenoid after the key is turned on, while the solenoid takes a large amount of energy directly from the vehicle’s batteries. 

This causes the solenoid to send the power to the starter motor, which will turn the flywheel with spins. 

Symptoms Of A Bad Starter Relay

Like every other electrical or mechanical component in your car, you can check if the starter relay is going to fail. Some of the signs are the same as the symptoms of a failing starter solenoid, while others can let you know if the starter motor will fail. 

1. Vehicle won’t start 

This is definitely the most common sign of a bad starter relay. If you try to turn on your vehicle and it doesn’t respond, it may be an indication of a failing starter relay. 

Regardless of how many times you try to start your car, the vehicle is not going to respond. Nonetheless, if you hear a clicking sound, it could mean that your starter relay can be saved. 

2. Starter relay stays on 

When you turn on the ignition switch, it sends electricity to the starter relay, which then transfers right to the starter solenoid. After this, the solenoid sends the current to the starter motor. 

Now, the flexplate will start rotating due to the energy that the starter motor received. On the other hand, turning off the ignition switch could have opposite results.

Both components should stop functioning. If this doesn’t work in this sequence and the relay stays on after the engine turns on, you may have a failing or a bad starter relay. 

Rapid Clicks Coming From The Starter

Starter relays tend to simulate a click sound, but if there is no crank, then the starter motor is not getting enough current from the relay to get the engine moving. Or your battery could be dead.

A relay is only functional when it’s able to send the correct amount of electric current to the starter. Less or high power can damage the entire system and the vehicle won’t start.

How do you troubleshoot a start relay

You can perform a test by yourself, and if you want to learn how to do it, keep reading. 

Test for binding by rotating the lock cylinder. If you notice that the rotation causes the starter motor to stop working, then you found the issue. Lubricate the lock cylinder with a liquid graphite solution or with a Teflon lube (dry). 

If rotating the lock cylinder didn’t stop the motor, then the problem could be related to a faulty relay. Furthermore, testing for a faulty relay requires professional assistance. 

To find out if the relay works, the mechanic will likely swap it out with a fresh model with a part number equivalent. If this still doesn’t fix the issue, the problem will likely involve the ignition switch wiring. 

Liam

Hi, I'm the initiator and writer of this blog. Cars were and will be my first love, and my favorite hobby, that's why I decided to start this blog and write about my discoveries and techniques to improve my cars or repair them.