Dan Ferrell writes about do-it-yourself car maintenance and repair. He has certifications in automation and control technology.
If Your Starter Clicks, the Usual Causes Are:
- A weak battery
- Loose, damaged, or corroded battery cables
- A faulty starter solenoid or relay
- A bad starter motor
- Too much ground resistance
The starter motor needs up to 250 amps or more (depending on the model) to produce the high torque necessary to turn the engine over. So anything that interferes with the needed current load will cause starter motor problems. Often, you'll hear this interference manifest itself as a click, or a series of fast clicks, at the starter solenoid or relay.
Most car owners can diagnose the problem using a simple series of tests with a digital multimeter (DMM). And these tests only take a few minutes.
Since most current flow, starter motor, or starter solenoid issues manifest as a single click or a series of clicks, you'll find a section for each condition. This will make it easier for you to diagnose the problem. If the first tests don't produce clear results, go over the tests in the other section to make sure you are not dealing with more than one issue.
So, let's start by briefly going over how a starter relay or solenoid works so you can make sense of the tests.
Contents of This Article
1. How a Starter Relay or Solenoid Works
2. I Can Hear the Starter Clicking Fast
• Starter insulated circuit resistance test
• Starter ground circuit resistance test
3. I Can Hear the Starter Clicking Once
• Starter solenoid or remote starter relay test
1. How a Starter Relay or Solenoid Works
A relay or solenoid is an electromagnetic switch. This device has a coil inside that produces a magnetic field when current flows through it. This magnetic field pulls a metal plunger that effectively connects two normally isolated electrical contacts or posts. These two posts connect the battery to the starter motor.
When you turn the ignition key to the Start position, you are sending electrical current to the relay or solenoid coil. The magnetic field then causes the plunger to move and bridge the two electrical contacts, allowing battery current to pass to the starter motor. Once the engine fires, the relay or solenoid disengages.
However, when there's not enough current to operate the starter motor, the magnetic field around the coil will pull and free the plunger in a repeated cycle for as long as you have the ignition key in the Start position. That's why you hear the series of clicks.
If full battery power makes it to the starter motor but nothing happens, the plunger in the solenoid remains fast against the two electrical contacts, waiting for the starter motor to turn the engine. With a faulty motor, solenoid or relay, though, nothing will happen. That’s why you may hear a single, solid click coming from the starter relay or solenoid.
2. I Can Hear the Starter Clicking Fast
Current flow issues in the starter circuit usually manifest as a series of fast clicks, or chattering, coming from the starter relay or starter solenoid. This is perhaps one of the most common starter system failures, probably because extreme temperatures, corrosion, and wire issues can have an adverse effect on current flow and the car battery itself.
The next tests will help you track the faulty part in the circuit that is preventing full current flow to the starter motor.
Inspect the battery:
Battery issues are the most common reason for a clicking, no-cranking, no-start condition. Make a quick inspection of the battery first:
- Check the case for damage.
Check the electrolyte level (on removable caps batteries).
- If necessary, add distilled water to the cells and charge the battery.
- Check the battery terminals and cables for looseness and corrosion.
Measure the battery state of charge:
Connect your DMM leads across the battery terminals:
- You should get 12.6 voltage across the battery terminals with accessories turned off and ambient battery temperature between 60 and 100 F (5.5 and 37.7 C).
- If you get a reading below 12.4 volts, your battery is not fully charged. There could be a problem with the battery itself, the charging system or the circuit.
Just keep in mind that this test doesn’t tell you whether the battery is capable of delivering the amperage your starter motor needs to operate properly. It just gives you an idea of the state of charge.
If you suspect a problem with the battery, you can use a hydrometer to troubleshoot battery condition, or have it tested in a car shop.
Next, you'll test the starting circuit.
Testing the Starter Insulated Circuit
This test focuses on the red, high-current cables that send battery power to the starter motor. Here, you'll check for voltage drop (resistance) in this part of the circuit using a digital multimeter.
A high voltage drop will reveal high resistance in the circuit, which can prevent the starter motor from functioning properly.
High resistance may be caused by:
- corroded cables or wires
- loose connections
- frayed wires
- carbon buildup in the relay or solenoid contacts
To test the insulated circuit:
Make sure you know whether your starter motor uses an on-starter solenoid (a cylinder mounted on top of the starter motor) or a remote-type relay, which usually mounts on the fender well and connects to the red battery cable.
- Disable the fuel system by removing the fuse for the fuel pump. Also, you can disable the ignition system by disconnecting the ignition module. Or use a remote starter switch. If necessary, consult your vehicle repair manual.
- Set the transmission to Park (automatic) or Neutral (manual).
- Set your voltmeter to the lowest range on the DC volts scale.
Connect your meter’s red lead to the positive (+) battery post, and the black lead to the starter terminal of the solenoid, or to the battery terminal on the starter, if your motor uses a remote-type relay.
Make sure to keep your meter’s leads away of moving engine parts during the test.
Have an assistant turn the ignition key to the Start position while you read the voltage drop on your meter.
Usually, you'll get a reading between 0.2 and 0.6 of volts drop. Between the ends of a single cable, usually you should get 0.1 of voltage drop.
- If you get a high voltage drop reading, repeat the test moving your black lead to the next connecting point in the insulated circuit towards the battery. Your last test point is between the positive battery post and the terminal connecting to the post.
- When you get a normal voltage drop reading, the problem is between that point and the previous high resistance or high voltage drop point.
- For on-starter solenoids, if the insulated-circuit voltage drop reading is within an acceptable range, troubleshoot the solenoid as described in section 2, I Can Hear the Starter Clicking Once.
- For remote-type relays, if you got a high voltage drop reading on the starter side terminal, but a normal voltage drop reading on the battery side terminal, troubleshoot the relay as described section 2, I Can Hear the Starter Clicking Once.
Testing the Starter's Ground Circuit Resistance
The ground circuit test checks the current return path in the start circuit. You should have your ignition or fuel system disabled, parking brake engaged, and your transmission in Park or Neutral.
- Connect your black meter lead to the negative (-) battery post.
- Connect your red meter lead to the starter motor case and keep your leads away from engine moving components.
Ask your assistant to turn the ignition key to the Start position while you read the voltage drop on your meter.
Usually, you should get a voltage drop not higher than 0.2 volts. If you get a higher reading:
- Move your red meter lead to a clear surface on the engine block, then to the chassis, and to the ground terminal connection of the battery, taking a voltage drop reading in each point.
- The problem point will be between the low voltage drop reading and the previous high voltage drop reading.
If you need a more detailed description of this circuit diagnostic, check this post on how to do a starter circuit voltage drop test.
3. I Can Hear the Starter Clicking Once
Often, starter motor issues manifest as a single, loud click coming from the starter relay or starter solenoid. Usually, this points to a faulty relay or solenoid, or a bad or jammed starter motor.
Try first to rock your car back and forth and see if this works. Or you can tap the starter motor with a hammer and try starting the engine again. If this works, you are good to go. If this happens again later on, then there's a problem with your starter motor, and you'll need to replace it.
If this doesn’t work, continue with the next steps.
The next tests help you confirm that battery voltage is present at the solenoid and, if necessary, check the components.
Battery Voltage Feed Test
- Disable the ignition or fuel system.
- Set your transmission to Park (automatic) or Neutral (manual), and engage the parking brake.
- Set your multimeter to a range higher than battery voltage, usually 20 volts, on the DC voltage scale.
- Connect your multimeter's red lead to the battery terminal on the starter solenoid or the battery-side terminal on the remote starter relay, and connect the multimeter's black meter lead to the battery's negative post.
Ask your assistant to turn the ignition key to the Start position and get your voltage reading. You should get battery voltage at the terminal.
- Otherwise, perform the insulated and ground circuit tests described in the previous section.
- If you get battery voltage, continue with the next solenoid or relay tests.
Starter Solenoid or Remote Starter Relay Test
This test helps you determine whether the starter solenoid or relay is working as it should:
- Set your transmission to Park (automatic) or Neutral (manual).
- Disable the ignition or fuel system to prevent the engine from starting.
- On an on-starter solenoid, connect your voltmeter's red lead to the solenoid battery terminal and the black lead to the starter motor strap.
- On a remote-type starter relay, connect your voltmeter's red lead to the battery terminal on the relay and the black lead to the starter terminal on the relay.
- Have an assistant turn the ignition key to the Start position.
Check your voltage drop:
- On an on-starter solenoid, if you get a voltage drop higher than 0.2 volts, make sure the heavy battery cable is not loose or corroded. If necessary, tighten the cable or clean the terminals and repeat the test. If you still get a high voltage drop, replace the starter solenoid or starter assembly.
- On remote-type starter relays, if you get a voltage drop higher than 0.2 volts, make sure the heavy cables are well connected and corrosion free. If necessary, disconnect the cables and make a visual inspection and repeat this test. If the solenoid fails the test again, replace the solenoid or motor assembly.
On remote-type starter relays:
- Unplug the thin wire from the relay’s control circuit terminal. You may also have a similar thin wire that connects to the ignition bypass terminal. Make sure you are unplugging the control circuit terminal.
- Set your DMM to the Ohms scale.
- Connect your meter leads across the control circuit terminal and the relay’s mounting bracket.
- You should not get a reading of more than 5 ohms. If you do, replace the relay.
Another reason why your solenoid would make a single click without being able to start the engine is because of a seized engine or ignition timing problem.
A seized engine could happen when:
- running the engine without oil
- the engine overheats and runs until it locks
- the ignition timing belt or chain breaks
If you suspect a seized engine, this other post can help you.
4. Dealing With a Starting Clicking Issue
In the video above you can find a quick summary of troubleshooting tips when your starter motor clicks or chatters.
Starter clicking issues are not uncommon, especially as your car ages. Yet, most of the time you'll be dealing with a wire, connection or component issue. Always pay attention to the number of clicks you hear when attempting to start your car.
- If you hear a chattering sound, most likely not enough current is getting to the starter motor.
- If you hear a single click, most likely there's something wrong with the starter motor, solenoid or relay.
Following the tests described here should help you diagnose the problem and get your car back on the road soon.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
Questions & Answers
Question: Are a starter solenoid and starter relay the same thing?
Answer: They both have the same function. Usually, the one mounted on the starter motor itself is called a solenoid. The remote type is called a starter relay, found in many Ford models.
© 2019 Dan Ferrell