How to Test a Tractor Starter Solenoid

A starter solenoid is a magnetic device situated inside the starter motor, and it is responsible for starting the engine when you turn the ignition key. The battery sends an electrical charge to the starter solenoid when you attempt to start the vehicle. This is how a tractor starter solenoid works. The starter solenoid is found in most vehicles, and sometimes it doesn’t work, which results in problems related to starting the engine. It is crucial to have the starter of your vehicle work properly.

The tractors and lawnmowers also have the starter solenoid, and we all know that these two are actual vehicles widely used in agriculture.

There is a prevalent sign of a bad starter when you attempt to start the engine, but it won’t start, which shows that either the problem is with your starter or with your battery, but in most cases, the problem is with your starter.

Now, you should know how to test a tractor starter solenoid so that you can find out if your tractor’s starter solenoid is working correctly or not.

How to Test a Tractor Starter Solenoid?

Testing the starter solenoid of your tractor is not a difficult job if you are equipped with some essential tools required in the testing process. You will get to know about those tools further in this article.

Check the battery

I have already mentioned that the battery needs to be working correctly and should be charged enough. Now you need to check the battery’s charge level, and for that, you will be required to have a voltmeter. Now, touch the red lead of your voltmeter with a positive post of the battery and let the black lead connect with the battery’s negative post.

Now, if you see the reading is lower than 12.5 volts, it means that your battery needs to be charged. This is the way to test the starter solenoid of your tractor that lacks the volts to start.

If you do not have a voltmeter, you can buy it from Amazon.

Check all the connections.

It is important to have all the electrical wires and cables working correctly to establish the proper connection. To ensure that wires and cables are working properly, you will have to test whether each connection between the solenoid, battery, and starter is proper or not. Check all the connections meticulously, and you may find some connections that could be affected by the corrosion, and this problem is sometimes the real cause why your engine won’t start.

The battery part can be located beneath the operator’s seat in the engine compartment, and the starter motor should stay mounted on the side of the engine. The solenoid is a small cylinder that is attached to a lawn tractor frame. You should find two wires attached to the solenoid in which one brings a connection from the starter motor, and another one is from the battery.

Another thin wire should be coming from the ignition key that activates the solenoid when the engine is in the start position. All of the cables that you read about should be checked thoroughly and if you find any corrosion or severe dirt, clean it up, but before that, disconnect the battery.

You will have to undo those connections that are corroded with the help of a wrench or screwdriver. Now, to get rid of those specks of dirt and corrosion, you can use sandpaper, and after you are done cleaning it, connect them back and make sure the connections are tight enough.

After all of these things, reconnect the battery and attempt to start the engine. If you have done everything correctly, it should start. So this is also a way to test a tractor starter solenoid.

Check if it needs a replacement.

If you won’t find your engine starting after fixing the connection problem, the problem is with something else, which could be the damaged solenoid.

Now, turn the ignition key on, go to the solenoid and look for the huge terminal posts. This is the place you find the thick red-colored wires connect to the solenoid. Now, bring the shaft part of the screwdriver and touch it at the huge terminals. If you see that the engine starts, it means that the solenoid is entirely damaged and needs to be replaced.

Here is one more thing. If the engine still won’t start, it means the motor itself is defective and needs to be replaced.

So these are the ways how to test a tractor starter solenoid. The same test processes imply lawn tractor solenoid. The testing starter solenoid is not a challenging task if you have the required tools.


So this was all about how to test a tractor starter solenoid. Starter solenoid plays a very important role in vehicles, and you should not overlook this problem because sometimes, you are in a hurry, and you attempt to start your vehicle, but it doesn’t start, which is very annoying. So make sure you get the starter solenoid fixed or replaced as soon as you find it not working correctly.

Frequently Asked Questions (FAQs)

Some frequently asked questions that may help you solve your query:

How many types of starters are there?

There are four types of starters: Full voltage reversing starter, Full voltage or Across the line starter, Reduced voltage starter, and Multi-speed starter. All of them are taken in different uses.

With the help of a multi-meter, you can also check for the resistance just by placing the red probe of the multimeter to the ignition circuit terminal and the other one to the ground terminal. If you find that the voltage reading is not 12 Volt when the ignition switch is turned on, it means that the starter relay is faulty. Another way of testing for resistance is the wire jumper that you can use.

There are so many signs that your tractor starter is going bad. Your tractor creates a cranking noise when you attempt to start it, or it doesn’t start even after multiple attempts. These are some of the common signs that your tractor starter solenoid is bad and needs to be replaced with a new one.

To test a starter solenoid with a multimeter, attach the red wire (positive wire) from the multimeter to the positive terminal on the solenoid. This is the terminal that goes to the starter. Now, place the black wire (negative wire) from your multimeter onto the terminal that comes from the battery. Now, have someone to start the vehicle. When the ignition is turned on, you should see a drop in the voltage. The target range is 0.5 V, but if you see more or less or no drop in the voltage, it means that your solenoid is at fault and needs to be replaced.

To wire it, connect the large red wire running to the starter to one of the large terminals on the solenoid. Now, connect the second large red wire, running to the battery, to the second terminal on the tractor solenoid. This is how you wire a tractor starter solenoid.

There is probably no way for a starter solenoid to drain the battery. Everything it does is establishing a connection from the battery cable to the starter cable. If your battery drains, it means that the fault is in your battery, and you may need to replace it with a new oneā€”the batteries of a lawnmower last for more than two years.

The process is quite similar to testing other solenoids. Get a jumper wire and connect its one end from the positive terminal of the battery and touch the small lug on the starter solenoid, marked ‘S’ with the other end to test the switch of the starter ignition. If you find the starter motor runs or turns over, it means that the starter ignition switch has a fault and needs to be replaced. This is how to test a starter solenoid on a lawn motor.

There are a couple of reasons why they can stick. If the battery is not charged, it can stick. Other potential reasons can be loose connections between the battery and solenoid, chanking too long, resulting in heating the inside, or a starter that pulls so many amps.

When the solenoid is going bad, it means that something happens or is happening, which results in inadequate or no current to the starter when you attempt to start the engine. Sometimes, internal corrosion may freeze the slug, which resists the current from flowing. You can remove the corrosion and reconnect the wires tight, and that may resolve your problem.

If you notice that your starter is clicking, the leading cause can be damaged, loose, or corroded battery cables that need to be fixed. Other causes can be a faulty starter solenoid or a bad starter motor.

During the engine cranking, the starter solenoid can draw 8 to 10 amps of current.

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