Nothing sucks more than having your car not start. Without your car, how can you get to work? To the grocery store? To get the kids to and from school? Well, this article will help you to troubleshoot the starter motor on your 2.4L GM (Quad 4) equipped vehicle.
Testing the starter motor on your 2.4L Pontiac Grand Am (or Cavalier, Malibu, Achieva, Alero, Sunfire) is not a hard test to do and can be accomplished with two tests. You don't need any exotic automotive diagnostic equipment to do it, just a multimeter.
Contents of this tutorial:
Before you jump into the two tests, let me tell you that both are On-Car tests of the starter motor and you don't have to remove it from you car to test it, although the photos I'm using to describe the tests show the starter motor off of the car.
Symptoms Of A Bad Starter Motor
The most common symptom of a bad starter are:
- You turn the key to crank up and start your GM 2.4L (Quad 4) car and nothing happens.
- You got someone to help your jump start you GM 2.4L (Quad 4), and this did not get the car or mini-van to crank.
- You've bought a brand new battery (thinking that was the solution to the 'no-crank' condition) and this did not get the car to crank and start.
- Turn the key to start your GM 2.4L (Quad 4) and all you hear is a small knock and nothing else.
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.
STARTER TEST 1: Verifying The Starter (S) Signal
One of the things that could make you think that the starter motor is bad, when it really isn't, is a bad battery or a discharged one. So, the first thing you have to do is make sure that you're starting these two tests with a fully charged battery.
Now, in case you're wondering how to test the battery on your car, you can do a very simple test to find out. Here are the steps: 1.) Turn on the headlights, with the engine off, for about 10 seconds and then turn them off. 2.) Now, measure the battery voltage with a multimeter. If the battery voltage is at least 12.4 Volts (which indicates your battery is at least 75% charged), then you can proceed with the tests in this article. If not, just charge your battery.
OK, for this first starter motor test, here's what you'll need to do:
Raise your 2.4L Quad 4 Chevy (or Pontiac, Olds, Buick) car and place it on jack stands (jack stands are important), since the starter motor can only be accessed from underneath the car.
OK, once the car is up and on jack stands, probe the wire that connects to the S terminal of the starter motor solenoid, with the red multimeter test lead. What I personally do is use a wire-piercing probe to pierce the wire and then attach the red multimeter test lead to this probe.
The S terminal on the starter solenoid??? This is the thinnest of the two wires that connects to the starter solenoid. The big thick wire comes from the battery positive post. The thinnest one (S terminal wire) comes from the ignition switch (via the neutral safety switch) and is the one that delivers the Start signal from the ignition switch.
Ground the black multimeter test lead on the battery negative (-) terminal or on a clean spot on the engine.
Now, the car won't crank, but when ready, have a helper crank the engine while you observe what voltage the multimeter will register on it's display screen.
You should see one of two results when you helper turns the key to crank the engine (although it's not gonna' start):
1.) 10 to 12 Volts DC if the ignition switch is working.
2.) 0 Volts if no Crank (Start) signal is present.
OK, let's make sense of the readings that your multimeter recorded in the test:
CASE 1: Your multimeter registered 10 to 12 Volts. This let's you know that both the ignition switch and the neutral safety switch are doing their job and supplying the Crank (Start) Signal.
Now, around 90% of the time, you could stop here and condemn the starter motor as bad and replace it and the problem would be solved. But to be absolutely sure, I suggest doing one more test.
The next test would be to voltage drop test the battery positive wire that connects to the starter motor with the nut. This is an easy and fast test, go to: STARTER TEST 2: Voltage Drop Testing The Battery Cable.
CASE 2: If your multimeter DID NOT register 10 to 12 Volts. This tells you that the either the ignition switch or the neutral safety switch or the starter relay is bad. Without this Start (Crank) signal, the starter motor will not come alive and crank the engine.
Now, it's beyond the scope of this article to test either the ignition switch, the neutral safety switch, and starter relay but you have at least eliminated the starter motor itself as bad.