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How to Determine If Your Starter Motor Is Faulty

A car that won't start can be the definition of frustration. Often, this can be caused by a faulty starter motor. To check if this is the issue, what do you need to look for?

What Are the Symptoms?

Firstly, you need to isolate if the problem is indeed caused by a faulty starter motor. Do you find that when you crank the ignition that nothing happens and the engine doesn't turn over at all? Alternatively, when you turn the key do you just hear one, frustrating click and nothing else? Thirdly, do you find that the engine will just turn over very lethargically when you try and start it, with no results?

Ruling out the Battery

You should first get a friend to connect jumper cables to your vehicle and try again, just to eliminate the battery as a potential cause. Assuming that the battery is good, there are a number of additional tests you can complete from here on.

Finding the Starter Motor

Open the bonnet of the car and have a look towards the back of the engine, close to where the engine meets with the gearbox casing. You should be able to identify the starter motor, as it is usually in the shape of a cylinder, which has a further (and smaller) cylinder attached to it. You will see a cable that is connected directly from the car's battery to this component.

Now, focus on the smaller cylinder which is attached to the side of the starter motor. This is known as the solenoid. It will have two terminals and the battery wire will connect to one of them.

Once again, crank the ignition (or get somebody else to do this for you) and listen for a noise. A click indicates the starter solenoid is working but the amount of electricity it is supplying to the starter is likely not enough to get your engine moving.

Testing Power Transfer

If you or a friend has a test light in the garage, connect it to the output terminal of the solenoid. Make sure that the other lead from the test light is grounded by connecting it to the body of the car against bare metal. If the light activates it means that the solenoid is receiving electricity properly.

Next, connect the test light to the lowest terminal on the solenoid. With the black lead still grounded turn over the ignition and see if the light comes on. This will now indicate that the solenoid is transferring power to the starter. Now, if the starter does not activate and crank the engine into life, then it will likely have to be replaced.

Tell your mechanic what you found, and that you suspect it is the starter motor, as opposed to the solenoid or the battery.