Sunday, March 20, 2011

How to test the starter solenoid?

What is a Starter Solenoid?

As you turn the ignition key, car's starter motor is switched on by power delivered by car battery, via solenoid. The starter solenoid is a relay that closes metal contacts with the starter motor, when it receives a current from car battery and ignition switch. As a result of current being delivered, the motor starts working. This makes a retractable rotating gear to engage with the flywheel and turn it to crank the engine. The starter solenoid thus provides power to drive starter motor.

So when your car doesn't start, it may be due to the malfunctioning of several parts that come into play ranging from the car battery to the retractable gear. There are two main types of starter solenoids. One type only acts as a switch which closes the circuit between battery and motor. The other type may act as a switch, as well as move the plunger that engages the gear with the flywheel. Insufficient power delivered from the car battery can be the reason for starter solenoid not being able to switch on the motor. Let us take a look at how to troubleshoot a starter solenoid.

How to Test a Starter Solenoid of a Car?

As I said before, if your car is not starting, there could be many defects in the entire link that you will need to check before you can narrow down to the starter solenoid is the culprit.

Put the car in neutral gear and let the parking brake be on. The first link in the chain is of course the car battery. You need to know how to check car battery and ensure that it is in a good working condition before you go ahead. Arm yourself with a voltmeter and check whether the battery output voltage is around 12 V. If it is, then you can proceed with the rest of starter solenoid testing procedure.

Next car part that could be the culprit for starter system not working is ignition switch.If the ignition switch is all right, then problem could be with starter motor itself. To check that, possibility directly connect car battery with starter motor to test working. If motor's working fine, then test car starter solenoid.

Locate the starter solenoid . Disconnect the wire that runs from ignition switch to solenoid. In order to test the starter solenoid, use insulated pliers or a screwdriver to short the big post on the starter solenoid, with the ignition switch terminal on the same device. This will directly transfer power to solenoid without the ignition switch current. Now ask somebody to turn on the ignition.

If your engine cranks with the ignition switch terminal shorted in this way, then your solenoid is in good working condition and the problem is elsewhere. Otherwise, if the engine doesn't crank, you'll have to replace the starter solenoid. In case, you are not confident about pulling off this procedure, take help from a car mechanic.