Understanding how to test a starter solenoid will help you overcome the worry about the proper functioning of the component, especially when the vehicle fails to start.
A vehicle’s starter solenoid is a crucial component that plays a vital role in starting the engine and ensuring that it runs efficiently. The component is located within the vehicle’s engine compartment near the starter motor.
So, if your vehicle suddenly fails to start and you’re wondering what could be wrong, ensure to test the solenoid, among other components.
This article provides a step-by-step guide to take you through the process. You will find out whether the solenoid is the issue or not after reading this article.
What Is a Starter Solenoid?
A starter solenoid is an essential electrical component in a vehicle’s starting system. When you turn the ignition key, it acts as a powerful switch that connects the battery to the starter motor.
It allows high current to flow from the battery to the starter, enabling the engine to crank and start. When you turn the key or press the start button, a small electrical signal is sent to the solenoid.
Then the solenoid uses an electromagnetic field to push a plunger that closes a set of heavy contacts. This movement allows full battery voltage to reach the starter motor.
Once the engine starts and you release the key, the solenoid disengages, cutting off the power to the starter. The starter solenoid is typically installed on top of or next to the starter motor, depending on the vehicle model.
A faulty solenoid can prevent the starter motor from receiving power, resulting in the vehicle failing to start or making a clicking sound when starting.
The starter solenoid is the link between your ignition switch and starter motor, making it a key part of getting your vehicle running.
When Do You Need to Test a Solenoid?
Solenoid testing is critical to application functioning under varying circumstances, which is why knowing how to test a solenoid coil is so important.
Solenoids, though small, are essential to many electrical and mechanical functions across industries and applications.
Solenoids, like any electrical device, should be tested before application installation, often referred to as bench testing, which we will explain in more detail later.
Therefore, testing solenoids is critical in the following situations to avoid any potential issues that may cause safety hazards or system failure.
- New installment or replacement
- Scheduled maintenance
- Performance issues
- System troubleshooting
- After significant environmental changes, like extreme temperature fluctuations or exposure to moisture
- Preventative testing when required
How to Test a Solenoid Step by Step Guide?
#1. Test a Solenoid with a Multimeter.
Solenoid multimeter testing involves checking its electrical resistance and verifying the continuity of the coil to ensure it is functioning correctly.
Multimeter testing accurately measures electrical properties like resistance, continuity, and voltage, which can help diagnose the functionality and identify faults in solenoids, ensuring they operate correctly in their applications.
To perform a multimeter test, you will need a digital or analog multimeter, any necessary tools to access the solenoid, and the solenoid user manual or data sheet to reference its resistance values.
Step 1: Ensure safety by turning off any power to the solenoid and disconnecting it from the circuit to avoid electrical hazards.
Step 2: Locate the solenoid.
Step 3: Turn on the multimeter and set it to ohms (Ω), which measures resistance.
Step 4: Find the solenoid’s terminals—the solenoid coil typically has two main terminals. Place one multimeter probe on one terminal of the solenoid coil and the other probe on the opposite terminal. Read the resistance value displayed on the multimeter.
Step 5: Compare the readings with the specified resistance range in the solenoid’s user manual or datasheet. The resistance readings should fall within this range.
- A very high resistance (infinite or no continuity) indicates an open coil, which means the solenoid is likely faulty.
- A very low resistance (close to 0 ohms) indicates a shorted coil, which is also a faulty indication.
#2. Test a Starter Solenoid Without a Multimeter.
If you don’t have a multimeter, you can still perform a basic check on your starter solenoid using a screwdriver or test light.
While this method is not precise enough, it can help you determine whether a starter solenoid is working properly or needs to be replaced.
Method 1: Using a Test Light.
#1. Locate the Starter Solenoid.
Find the solenoid installed on or near the starter motor. Identify the battery terminal, starter terminal, and control terminal.
#2. Check for Power at the Battery Terminal.
- Clip the test light’s ground lead to a clean metal surface on the vehicle.
- Touch the probe to the solenoid’s battery terminal.
- If the light turns on, power is reaching the solenoid.
- If not, there’s likely a problem with the battery or cable connection.
#3. Check the Control Terminal Signal.
- Have a helper turn the ignition key to the “Start” position.
- Touch the test light probe to the small control terminal.
- When the key is turned, the light should come on; if it doesn’t, the issue is with the ignition switch or wiring, not the solenoid.
#4. Check Power Output to the Starter.
- Keep the ignition in the “Start” position.
- Touch the probe to the starter terminal on the solenoid.
- If the light illuminates, the solenoid is sending power to the starter motor.
- If the light doesn’t turn on, the solenoid is faulty and needs replacement.
Method 2: Listening for the Solenoid Click.
1.Sit in the driver’s seat and turn the ignition key to “Start.”
2.Listen for a clicking sound from the solenoid or starter motor area.
- Single strong click: The solenoid is engaging normally.
- Rapid clicking: Weak battery or poor connection.
- No click: The solenoid may be defective or not receiving power.
Method 3: Checking Solenoid Function by Bypassing.
Safety Warning: This test involves direct electrical connections. Please only perform it if you have sufficient confidence and operate with caution.
- Ensure the vehicle is in park (or neutral for manuals) and the parking brake is engaged.
2. Use an insulated screwdriver to connect the battery terminal and the starter terminal on the solenoid.
3. Observe the following:
- Engine cranks: The starter motor is good, but the solenoid isn’t activating — it’s likely faulty.
- Nothing happens: The problem may be with the starter motor or battery.
Summary
Testing without a multimeter can still provide valuable clues:
- Click but no crank: Solenoid stuck or worn.
- No click, no power: Bad solenoid or wiring issue.
- Engine cranks when bypassed: Solenoid is faulty.
#3. Test a Solenoid With a Battery.
Don’t have a multimeter on hand? That’s not a problem. Here is how to test a solenoid without a multimeter using a battery instead. Testing with a battery is a straightforward method to check if the solenoid correctly activates when power is applied.
To test a solenoid utilizing this method, you will need a battery that matches the solenoid’s voltage rating, insulated jumper wires with alligator clips, and protective safety gloves and goggles.
Step 1: Ensure safety by turning off any power to the solenoid and disconnecting it from the circuit to avoid electrical hazards.
Step 2: Find the solenoid’s terminals—the solenoid coil typically has two main terminals.
Step 3: make sure the battery is fully charged and matches the voltage rating of the solenoid. For example, a 12V solenoid will use a 12V battery.
Step 4: Connect the battery to the solenoid using the insulated jumper wires with alligator clips. Connect the positive terminal of the battery to one of the solenoid’s coil terminals and the negative terminal of the battery to the other coil terminal.
Step 5: When the battery is connected, the solenoid should activate, emitting an audible clicking sound. No audible clicking typically indicates a faulty solenoid.
Step 6: Once finished, disconnect the jumper wires from the battery and the solenoid.
#4. Test a Starter Solenoid with a Screwdriver.
If you don’t have a multimeter, testing the starter solenoid switch with a screwdriver is one of the simplest and most direct methods.
This method allows you to check whether the solenoid and starter motor are working. You need to manually connect their terminals to complete the circuit.
However, this must be done with extreme care because it involves a large current from the battery.
Step 1: Prepare for Safety.
- Ensure the vehicle is in park or neutral, and engage the parking brake.
- Turn the ignition key off to prevent accidental starts.
- Wear insulated gloves and safety goggles — sparks may occur during the test.
Step 2: Locate the Starter Solenoid.
- The starter solenoid is usually installed on the top or side of the starter motor.
- Identify its two large terminals:
Battery terminal (B+) – connected to the positive battery cable.
Starter terminal (M) – connected to the starter motor.
- There’s also a small control terminal (S) that receives the ignition signal.
Step 3: Connect the Terminals.
- Hold the insulated handle of a metal screwdriver.
2. Touch the screwdriver blade to both large terminals (B+ and M) on the solenoid simultaneously.
3. Observe what happens:
- If the starter motor cranks: The starter motor is functional, but the solenoid may not be engaging through the ignition circuit —— a wiring or control issue.
- If nothing happens: The solenoid is likely defective, or the starter motor itself has failed.
Tip: You may see sparks — this is normal due to the high current flow. Keep the contact brief (1–2 seconds) to avoid overheating or damage.
Step 4: Test the Solenoid Activation (Optional).
- Have a helper turn the ignition key to the “Start” position.
- At the same time, gently touch the small control terminal (S) and the battery terminal (B+) with a screwdriver.
- If the solenoid clicks or the starter motor engages, the solenoid coil is functional.
- If there’s no click, the solenoid coil or internal contacts are faulty.
Step 5: Interpret the Results.
| Observation | Possible Issue |
|---|---|
| Engine cranks when connected | Faulty solenoid control circuit or ignition switch |
| No crank, no spark | Bad solenoid or starter motor |
| Clicks but doesn’t turn engine | Weak battery, corroded terminals, or damaged solenoid contacts |
How do you fix a solenoid?
If your vehicle’s solenoid is having an issue, attempting to fix it can restore it instead of running off to buy a new solenoid for replacement. So, follow this procedure to fix your vehicle’s solenoid.
#1. Remove the starter.
Firstly, get your vehicle to park properly by engaging the emergency brake or neutral. Then, open the hood and disconnect the battery’s negative terminal.
After that, get a floor jack to raise the vehicle and place two jack stands beneath the frame close to each wheel. Then, remove the starter by following the procedure on your car manufacturer’s manual.
#2. Take out the main starter wire.
Get under the vehicle and take out the main starter wire, as well as two to three ignition wires at the back of the solenoid.
#3. Remove the mounting bolts on the starter.
Next, remove the bolts that hold the starter in place with the correct socket. Then, pull off the starter by turning and twisting it until it is out of its mounting position. After that, place the starter motor in a vice and clamp the case gently.
Now, remove the wire connecting the solenoid to the starter. Ensure to use a good screwdriver to take off the solenoid’s backing plate.
#4. Pull out the round plunger.
Locate the round plunger; it’s pretty small. Then, pull it out and keep the small ball and spring in a safe place.
Also, note the way the ball and spring fit on the plunger so that you can fix it appropriately. Next, remove the studs that hold the copper and remove the old copper.
#5. Install the new copper.
Now place the new copper in place and fix the two stud bolts; then, tighten them properly. After that, get the ball and spring; then load them in place into the plunger. After that, push the plunger into the starter solenoid.
#6. Replace the plates on the solenoid and reconnect everything.
Get the plates back on the solenoid. If they had bolts on them, ensure to bolt them in place properly. After that, fix everything else in the reverse order that you removed them; from the starter wire to the ignition wire, etc.
Now, take off the jack. After that, you can start the vehicle as much as possible and ensure that the solenoid makes good contact.
How much does it cost to fix a solenoid?
The estimated cost of fixing a solenoid depends on the vehicle’s make and model. While some may be relatively cheap, others may be quite expensive, as the case may be. Typically, the cost of fixing a single solenoid ranges between $200 and $500.
On the other hand, if you are replacing an entire solenoid pack, it will cost around $250 to $700. The total cost covers the parts and labor fee, respectively.
So, your total budget will depend on whether you’re fixing a single solenoid or a pack. However, ensure to find out how to test a solenoid coil and other parts of the solenoid before buying an entire pack.
FAQs.
Q: Why would a solenoid not work?
A solenoid may fail to work for several reasons, including inappropriate voltage, electric spike, contact with liquid, etc. The solenoid is responsible for converting electrical energy into useful mechanical work.
Since the solenoid deals with electricity, any slight changes in the voltage to an improper level will cause the coil to either burn out or fail. On the other hand, an unexpected spike or surge in electricity can also affect the coil and result in the solenoid’s inability to work.
Lastly, water can lead to several damages within a car, and the solenoid is not free from this reality.
Water and other liquids have the tendency to damage the coil and cause it to fail. Endeavor to pay attention to symptoms of a bad solenoid in transmission to fix the issue quickly.
Q: How do you check if a solenoid is working?
Checking whether a solenoid is working is pretty straightforward. So, if your car fails to start and you suspect that your vehicle’s solenoid isn’t working, do not hurry into concluding.
First, test to check whether the issue is with the solenoid or another component in the vehicle.
Follow this procedure to check if your vehicle’s solenoid is working or not. Meanwhile, you need a multimeter, jumper cables, protective gloves, and eyewear to do the check perfectly. This information is also useful to those asking how to test a 4 port solenoid.
Firstly, locate the solenoid on the starter; you need to open the hood and locate the starter in the engine. The starter is a large cylinder that has a smaller cylinder on it (this is the solenoid).
After identifying the solenoid, get a friend to start your car while you listen to a clicking sound from the solenoid. Ensure to maintain a distant position from the engine.
Once your friend starts the car, and you hear a loud clicking sound, it means the solenoid is working. You can also find out how to test solenoid with a battery as an alternative for the sake of experimenting.
Q: What is the resistance of a solenoid?
Using a multimeter to check the resistance of a solenoid has a lot to say about the solenoid, whether it has an open circuit, a short circuit, or it is partially shorted.
The resistance of a solenoid under an ideal condition should be around 0-100 Ohms or thereabout. For example, a solenoid that reads resistance of about 10 Ohms at 20 degrees centigrade will have a 9.2 Ohms resistance at 0 degrees centigrade.
Meanwhile, a solenoid at 80 degrees centigrade will have a 12.4 Ohms resistance. It is vital to understand that having k-ohm range resistance is not good. Also, if the solenoid reads as low as 1-2 Ohms, you probably have a shorted circuit.
Q: How do you jump a starter solenoid?
If your car fails to start and you suspect that the issue may be the starter solenoid, you may want to jump that component.
Understanding how to test a solenoid with a screwdriver will be helpful at this point. In order to jump a starter solenoid, simply get an insulated screwdriver with a metal blade.
After that, place the screwdriver’s metal blade against the 2 metal contacts (terminals) at the back of the solenoid. Then, ask a friend who’s available to help you turn the car’s ignition key to start position.
Once you do this, you will hear a humming sound from the starter motor, which reveals that it is okay, but the solenoid is faulty. On the other hand, you may hear a choppy sound which signifies that the fault is from the starter motor.
Q: Are solenoids repairable?
Of course, a vehicle’s solenoid is repairable; hence, you don’t need a new replacement whenever you notice a malfunction of the component.
Some car owners are usually anxious whenever their car develops a fault. They are quick to conclude that a component needs a replacement.
However, while there are faults that may require the replacement of the faulty components, the solenoid may not require a replacement in most cases. A quick diagnosis and repair can restore the component back in shape to function properly.
Q: What wires go to the starter solenoid?
A starter solenoid has three wires that connect to the three terminals of the component. The battery terminal known as the “B” terminal connects the starter solenoid to the battery’s positive cable.
Meanwhile, the start terminal known as the “S” terminal receives the power output from the vehicle’s ignition switch. Lastly, the motor terminal known as the “M” terminal is the one that is attached to the cable which connects to the vehicle’s starter motor.
When you turn your car’s ignition key to start the car, it sends voltage to the “S” terminal. Then, the voltage automatically energizes the electromagnetic windings of the solenoid, which pulls the plunger of the starter, making it push a disc to a set of contacts.
The contacts are attached to the “M” and “B” terminals. Current travels from the battery to the car’s starter motor, which cranks the engine to start once the contact establishes a connection.
Final Words
This article has just unveiled the step-by-step guide on how to test a solenoid. So, if you’re experiencing difficulty starting your car, ensure to engage the information provided in this article to verify if the issue is the solenoid.
However, the process will be pretty much easier for DIY enthusiasts than the average car owner, who may not know much about automobiles. So, if you’re not a DIYer, kindly contact an expert auto mechanic to help you with the test.