To repair a starter solenoid, find the electrical connectors on the solenoid, and determine which one is positive and which one is negative. Attach a voltmeter to the connections to check if it is getting a sufficient amount of power. After that, apply current to the car battery to make sure that the solenoid is working properly.Continue Reading
Before starting to test the starter solenoid, make sure that you can access it. Place ramps or jack stands under the car if the solenoid is located on the bottom of the car. If there isn't enough space around the solenoid, temporarily take out some parts. The positive connection on the starter solenoid is the braided wire attached to the post and to the starter.
Attach the positive lead of the voltmeter to the positive solenoid connection. Make sure to ground the negative lead of the voltmeter. Ask somebody to start the car, and watch the voltmeter. If everything is fine, the voltmeter is going to read 12 volts. If the battery or the ignition switch is faulty, the voltmeter is going to read less than 12 volts.
To test a starter solenoid with current directly from the battery, take out the ignition switch wire from the solenoid, and connect the positive post on the solenoid to the terminal where the ignition switch connects. Make sure to use an insulated screwdriver for this. If this doesn't activate the solenoid, there is a problem with the ignition switch or the solenoid is too old.Learn more about Car Parts & Maintenance