If you've been looking for a detailed step-by-step starter motor test, well you've found it. This article will show you how to test the starter motor on your GM 4.3L, 5.0L, or 5.7L pick up, van or mini-van.
Having your pick up (or van or mini-van) not start sucks, but having to diagnose and troubleshoot the problem doesn't have to.
To see if this starter motor test tutorial covers your specific Cadillac, or Chevy or GMC or Olds or Isuzu vehicle, you can take a look at the list of applications on the box labeled 'Applies To:' and scroll with the prev and next buttons.
Contents of this tutorial:
Before you jump into the tests, I recommend you read the entire article first. Also, you'll notice that the photos I'm using are of a starter off of the vehicle, this is just to make it easier to show you what you need to probe with your multimeter. The two tests in this article are on-car tests. So, don't remove the starter motor from your pick up (or van or mini-van).
Symptoms Of A Bad Starter Motor
The most common symptom of a bad starter are:
- Engine Does Not Turn Over (Crank): When you turn the key to start the vehicle, if the starter is bad, the engine will not turn over or crank. You may hear a clicking sound or no sound at all, indicating that the starter motor is not engaging with the flywheel to initiate the engine's rotation.
- Jump Start Ineffectiveness: If the starter is faulty, jump-starting the vehicle will not resolve the issue. Even with a boost from another vehicle's battery, if the starter is not functioning properly, the engine will still refuse to crank when you attempt to start the vehicle.
- Battery Charging or Replacement: Sometimes, a weak or dead battery can mimic symptoms of a bad starter. If you've charged the battery or replaced it with a new one, and the vehicle still fails to crank, it suggests that the problem lies with the starter rather than the battery.
- Hearing a Small Knock: When attempting to start the vehicle, if you only hear a small knock or click from the starter solenoid but no other sounds, it indicates that the starter motor is failing to engage with the flywheel. This can be a sign of worn-out starter components or a faulty solenoid, preventing the starter motor from turning over the engine.
Although the above list is a not a very complete list of symptoms, the theme that runs thru' them, and any other related symptom, is that the engine will not turn over when the key is turned to crank the vehicle.
Important Safety Precautions
SUGGESTION 1: The test explained in this tutorial is an on-car test of the starter motor. Do not remove the starter motor from the vehicle to perform the test steps in this article. Although the photos I'm using show the starter motor off of the vehicle; this is just to make it easier to point out where you need to make your connections.
SUGGESTION 2: It's critical that you make sure your battery is fully charged before you start any of the tests in this tutorial. Also, the battery cable terminals and battery posts must be clean and corrosion free.
SUGGESTION 3: Use jack stands to keep your GM vehicle up in the air. Don't trust the jack alone! Take all necessary safety precautions, like using jack stands to hold up the vehicle, wearing eye-protection (safety glasses), etc.
SUGGESTION 4: Remove the key from the ignition switch. This will prevent the engine from starting, in case the starter motor is OK.
SUGGESTION 5: If your vehicle has a standard transmission, make sure that it's out of gear and in neutral, and the parking brake is activated/on.
What Tools Do I Need To Test The Starter Motor
The one tool that I recommend to use to test the starter motor is a remote starter switch (like the Actron CP7853). Here are the two things I like the most about this tool:
- Remote Activation: The remote starter switch allows you to remotely activate the starter motor without having to access the ignition switch inside the vehicle. This can be particularly useful when working alone or when needing to test the starter motor from underneath the vehicle.
- Diagnostic Testing: By connecting the remote starter switch to the starter motor's solenoid terminal and battery, you can bypass the ignition switch and directly engage the starter motor. This enables you to perform diagnostic tests on the starter motor to determine if it's functioning properly or if there are any issues with its operation.
STARTER TEST 1: Applying 12 V To The S Terminal
The first we're gonna' do is manually apply 12 Volts to the starter motor with a remote starter switch.
This first test will either eliminate or condemn the starter motor as bad right off the bat.
If you don't own a remote starter switch, you can run down to your local auto parts store (like AutoZone or O'Reilly Auto Parts) and buy one from there. If you need to see what one looks like, you can see it here: Actron CP7853 Remote Starter Switch For 6V And 12V Automotive Starting Systems.
OK, this is what you'll need to do:
- 1
Raise and place your vehicle on jack stands. The only way to gain access to the starter motor is from underneath the vehicle.
- 2
Disconnect the wire that attaches to the S terminal of the starter motor solenoid.
- 3
Connect one end of the remote start switch to the S terminal on the starter motor solenoid.
- 4
Connect the other end of the remote start switch to the battery positive (+) post.
- 5
Apply 12 Volts to the S terminal of the starter motor solenoid.
- 6
You'll get one of two results:
1.) The starter will activate and will turn over the engine.
2.) The starter motor won't do a thing.
Let's take a look at what your test results mean:
CASE 1: The starter motor cranked the engine. This means that the starter motor is good and that you have an electrical issue keeping the starter motor from cranking the engine.
Also, since the starter motor did come alive and cranked the engine, this result lets you know beyond a shadow of a doubt that the starter motor is good and that you need to look at the ignition switch, or neutral safety switch as the cause of the no-start condition on your car or mini-van. Go to: STARTER TEST 2: Verifying The START Signal.
CASE 2: The starter motor DID NOT crank the engine. This usually means that your starter motor is bad and needs to be rebuilt or replaced.
I suggest one more test and this is to test the battery cable (that attaches to the starter motor) for corrosion. This can be accomplished very easily with a voltage drop test. Go to: STARTER TEST 3: Voltage Drop Testing The BAT + Cable.
