Diagnosing and Replacing a Bad Car Starter

When you press your car’s start button (or turn the key), you expect the familiar tune of the engine whirring to life. Silence is not golden when you have places to go. If there’s no sound or just clicking under the hood, you should replace the car starter or solenoid.

While modern cars often have complicated electronics under the hood, the starter is straightforward and easy to replace.

Getting Started With Starters

You can see the starter and solenoid on the bottom of this Chevrolet 383 crate engine.

Two components are integral to firing up your car’s engine: a starter motor and a solenoid. The starter engages a flywheel that turns the engine over until the fuel and spark plugs are in operation.

When engaged, these teeth on the starter motor gear, spin the engine’s flywheel.

The solenoid is a small cylindrical device attached directly to the starter motor. It has two purposes: It acts as a relay or switch, allowing current from the battery to reach the starter motor; and it thrusts the starter motor’s gear against the flywheel.

Once the car starts and you let off the ignition, the solenoid disengages. This allows the teeth on the starter motor gear to pull back from the flywheel. Otherwise, the gear would stay in contact and quickly wear out.

Troubleshooting and Buying Replacement Car Starter

If your car won’t start, it’s typically because the starter motor or solenoid failed. Troubleshooting should begin, however, with the battery. A car battery can fail without warning. Some dash lights may come on, but there might not enough power to start the engine. Also, check the electrical connections for corrosion.

If the battery is fine, the problem is likely with the solenoid or starter.

• When you turn the key, if you hear nothing, it’s probably a faulty solenoid.
• If you hear a whirring or a click, the starter is the issue.

The starter/solenoid for a Subaru is on the top of the engine, tucked under some heater hose.

In the past, it was cheaper to buy either the solenoid or the starter. Recently, starters have become commodities and the two are commonly sold together. It’s faster and more economical to slap in a new starter and solenoid assembly than it is to replace one component but not the other. You’ll also mitigate the risk of the other component failing soon after the first fix.

Replacement Steps

• Disconnect the negative (black) cable from the battery.
• To find the starter, follow the positive (red) lead from the battery. It will lead you to the starter. In older American-made cars with V-8s, the starter is usually accessible from under the engine. Use a set of stable jack stands or a ramp to gain access. The starter is accessible from the top of the engine compartment in many cars with smaller engines.
• Undo the wiring attached to the starter and solenoid. In older cars, it is usually a set of wires with ring terminals that slide on a stud and are secured with nuts. In newer cars, unclip the weather-sealed connector. Be sure to note where wires go before removing them.
• Most starters are secured to the engine block by two long bolts. Unbolt the starter and remove it with the attached solenoid.
• Bolt the replacement in place, connect the wiring, and test the results by starting your car. Voilà. The vehicle should now start effortlessly.

Some solenoids use ring terminals to attach to these metal studs.

eBay Motors has a large selection of replacement starters and solenoids. First, use eBay Motors fitment tools to buy the right pieces. Then, with the correct replacement starter in hand and one hour of work, your car will be good to go.