How To Test The Starter Motor On The Car (Step-By-Step)

How To Test The Starter Motor On The Car (Step-By-Step)

Testing a starter motor on the car or truck is a pretty easy test. I'll take you thru' this starter test step by step.

This 'How To Test The Starter' article applies to anything out there rolling around on pavement (automobile-wise). Whether it's a Ford, Chevrolet, Nissan, Toyota, Honda, or whatever or wherever on the planet, this info will help you.

The starter on your vehicle (car, pick-up, van, mini-van, etc.) may not resemble the starter motor on the photo. This is no cause for concern. Your starter motor will be similar and IS tested in the way described in this article.

Common Symptoms Of A Bad Starter

Before we start you may want to know what are some of the most common symptoms of a bad starter:

  1. When you turn the key to crank the engine, nothing happens. The engine will not turn over.
  2. When you turn the key to crank the engine and all you hear is one loud click. The engine will not turn over.
  3. Or you turn the key to crank the engine and the engine turns over very but very slowly and then stops.
  4. The battery is good. You know that because:
    • You bought a new one thinking that was the solution to the problem.
    • Or got someone to help you jump-start the vehicle to no avail.

Summary Of The On Car Starter Test

This is a brief summary of the tests we'll be doing to get to the bottom of what's causing a NO-CRANK condition on your car or truck. In my experience (as an automotive technician), I'd say that around 80% of the time, the result of this starter test will be that you have a bad starter on your hands.

The other 19% percent of the time it'll be a bad battery. The remaining 1% of the time it'll be some other issue.

With the tests in this 'how to test the starter' article you'll be able to either say with absolute certainty it is a bad starter motor or completely eliminate it as the cause of the DOES-NOT-CRANK condition. These are the testing steps:

  1. Test the battery first. This is a simple multimeter test.
  2. Test that the starter motor is receiving 12 Volts on its battery circuit.
  3. Test that the starter motor is receiving the START signal from the ignition switch.
  4. Voltage drop test the starter battery and Ground circuits. These two tests are very easy. I'll explain them step by step.
  5. Using a jumper-wire or an appropriate tool, apply 12 Volts to the START signal wire.
  6. Turning the engine by hand to eliminate a locked-up engine or a locked-up A/C compressor.
  7. If necessary, bench-testing the starter motor.

Safety Guidelines To Test The Starter Motor

The only thing that complicates the testing of the starter motor is its location on the engine. Some vehicles have it hidden in the back of the engine under the intake manifold. Some vehicles have it right up front in view and with lots of space to physically access it.

It doesn't matter where it's at, these tests apply. Whether the starter motor has to be accessed from the bottom of the vehicle or not here are some safety guidelines.

  1. If you have to lift up the car or truck to access the starter motor:
    • Use jack-stands to support the car or truck off the ground.
    • Use safety glasses while working underneath the vehicle.
  2. You'll need a helper:
    • To crank the engine as you perform some of the tests.
    • To help you perform the very important voltage drop test.
  3. When jumpering 12 Volts to the S terminal wire (circuit) make sure you don't short-to-ground your jumper wire.
  4. Be careful, take all safety precautions and use common sense.

Alright, let's get started.