Knowing how to test a starter or other automotive accessories is a valuable skill that can help you identify problems associated with your vehicle’s cranking process. When faced with a car that refuses to crank or exhibits peculiar sounds during ignition attempts, a test light can be your diagnostic ally. In this guide, we’ll demystify the process for you, focusing on practical steps and clear explanations.
We will do a test to check voltage drop while the starter is mounted in the vehicle. So, buckle up, and let’s shed light on how to troubleshoot your vehicle’s starter like a seasoned electrical expert.
Symptoms of a bad starter:
Here are few common symptoms of a fault with the starter for you to identify the problem:
Signs of low voltage:
When your car’s starter is dealing with low voltage, a few signs can clue you in on the issue. First off, you might notice insufficient engagement of the starter motor due to a drop in voltage on the solenoid terminal. This incomplete engagement can lead to a weak or erratic engine cranking. Additionally, the starter motor itself may operate weakly, causing slow or ineffective cranking, especially if it’s not getting enough voltage. Intermittent starting problems may arise, creating frustration for drivers as the car starts inconsistently. The continuous struggle with low voltage can also wear down starter components faster, potentially leading to a premature failure. Keep an eye out for delayed cranking, a noticeable hesitation or sluggishness when turning the key, and in severe cases, a significant voltage drop can result in a complete no-start condition.
1: No Crank, No Start
What it feels like: You turn the key, and nothing happens. Your car seems to be on strike. Something’s wonky inside the starter—maybe the solenoid isn’t doing its job or the brushes are too worn to pass the needed electrical current.
2: One-Click Sound
What it feels like: You try starting your car, and all you hear is a single click. The solenoid is trying to make things happen, but the starter isn’t cooperating, likely due to an internal electrical glitch.
3: Dashboard Lights Dimming
When you attempt to start the car, you might notice that the dashboard lights dim significantly. This suggests that the starter is drawing too much power, which can be a sign of a problem.
4: Slow Cranking
If you notice that the engine cranks very slowly when you try to start the car, it could be a sign that the starter is not functioning properly. This may be accompanied by a whining or grinding noise.
5: Starter Running, Engine Not
What it feels like: You hear the starter humming away, but the engine is taking a break. The starter is doing its job, but the pinion gear isn’t connecting with the flywheel—it’s like the starter is spinning its wheels without making progress.
6: Freewheeling
Freewheeling occurs when you hear a whirring noise without the engine turning over. This can indicate a problem with the starter drive gear not engaging properly.
7: Grinding Noise
What it feels like: You hear a grinding noise when starting. The pinion gear might be grumpy or damaged, especially when in motion with the flywheel.
How to Test Starter with Test Light?
In a properly functioning system, the solenoid terminal (S) receives a signal from the ignition switch when you turn the key to the “start” position. This signal activates the starter solenoid, which, in turn, engages the starter motor.
When you crank the engine with the test light connected to the solenoid terminal, your test light should stay lit. This indicates that the signal from the ignition switch is reaching the solenoid, and it’s engaging the starter.
If the test light goes out while cranking, it suggests a voltage drop issue on the heavy wire leading to the starter. A voltage drop occurs when there is an unwanted resistance in the circuit, hindering the flow of electrical current. The test light, being a low-resistance device, is affected by this voltage drop.
The light going out during cranking indicates that there is a significant voltage drop on the heavy wire supplying power to the starter. This could be due to a loose or corroded connection, a damaged cable, or other issues causing resistance in the circuit.
Step 1: Connect the test light & test the ground (starter housing)
Get yourself a basic test light. Connect the clip to the car’s battery negative (ground) and the probe to the starter motor housing. If the light doesn’t turn on, it means you have a good ground. If it does illuminate, there might be a bad ground connection.
Step 2: Test the starter’s battery terminal
The starter has a large terminal known as the battery terminal and is marked by B+ or BAT sign that’s always hot. Crank the engine while touching the test light to this terminal. If the light stays on, that’s normal because the starter is drawing a lot of current.
Step 3: Test the solenoid terminal
The smaller terminal on the starter is the solenoid terminal and is marked with S or SOL. Move the test light to the smaller terminal on the starter. Crank the engine again.
When turning the key to start your vehicle, pay attention to a distinct clicking sound; this indicates the engagement of the starter solenoid. If no click is heard, it suggests a potential issue with the solenoid. In the case of audible clicking, there may still be insufficient engagement, warranting further inspection.
If the light goes out, you’ve got a voltage drop issue on the heavy wire leading to the starter.
Step 2: Inspect the Connections
Tighten the nut on the terminals to ensure a good connection. If it was loose or dirty, this could be the cause of your starting problem.
How to Test Starter with Jumper Cables?
To check if your starter is working and you’re just n average guy like me, it’s actually pretty straightforward with just a battery, a couple of jumper cables and a screwdriver. First grab your jumper cables and connect the red one to the positive side of your car battery and the black one to the negative side. Now, take that black cable and attach it to the case of the starter anywhere you can get a good contact. On the starter, find the fat stud and the skinny one next to it. The fat one is where you hook up the positive cable. Now, take a screwdriver and touch it to the small stud labelled ‘S.’ This should make the starter come to life – you’ll see the gear pop out and spin. If that happens, your starter is in good shape. If not, it might be time to look into further troubleshooting. You can also check the solenoid separately by connecting the positive cable just to the ‘S’ terminal. If the pinion gear pops out, the solenoid is doing its job. And to test the motor, just touch the big stud on the starter body – it should spin.
How to diagnose a starter?
- Check Other Issues First: Before looking at the starter, make sure the problem isn’t with the battery, gears, or key connection. If you hear strange sounds like clicks or grinds, it might be the starter.
- Check Battery: First things first, let’s check the battery. Turn your key to the “on” position, switch on the heater, fan, and wipers, and take a peek at the headlights. If they’re nice and bright, your battery is good to go. You can also try jumping the vehicle if you have jumper cables.
- Locate the Starter: Find where the starter is located, either under the hood or underneath the car. If it’s under the car, use a jack to lift it safely.
- Tap the Starter: It’s a simple trick to gently tap the starter with a wrench or hammerand check if the problem is solved. Sometimes, a small tap can fix issues.
- Fuse and Relay Inspection: Examine the starter relay fuse and starter relay. Ensure they are not blown, and the relay clicks when tested.
- Label and Disconnect Wires: Label the wires connected to the starter with masking tape so you can reconnect them correctly later. Consult the car repair manual for guidance.
- Remove the Starter: Use a ratchet and wrench set to disconnect the cables and bolts holding the starter. Auto parts stores can test the starter for free.
- Inspect for Damage: Check the starter for any visible damage. If there’s a jam or loose cable, fix it. Reattach the starter.
- Test and Replace if Necessary: If the starter still doesn’t work, you may need to buy a new one. Either fix the existing one or replace it, and your car should be good to go.
Conclusion:
Testing a starter with a test light is a straightforward process that can diagnose various issues affecting your vehicle’s starting system. By systematically assessing the battery terminal, solenoid terminal, and associated connections, you can identify potential problems such as voltage drops and inadequate engagement. Understanding the significance of a consistent test light illumination during cranking is crucial, as it indicates a well-functioning electrical circuit. Additionally, addressing issues with a bad starter solenoid, weak starter motor, and intermittent starting problems can prevent premature wear and ensure reliable engine cranking. For those opting to use jumper cables for testing, the provided steps offer a simple and effective way to assess the starter’s condition.