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Starter and Alternator Repair

Engine Starter and Solenoid

Starter and Alternator Repair Tips

Key components of the electrical system in any vehicle are the starter and the alternator. The starter is a motor that cranks the engine (turns it over) in order to build compression and get it started. The alternator is a generator that uses the engine's power to produce electricity to store in the battery and be used in the vehicle's operations.

Common Problems With Starters

Two key indicators of a bad starter or starter coil are: engine "clicks" but does not turn over or the starter makes a whining or grinding noise when the key is turned to start the car.

Clicking But Not Starting

In the first case, the problem could be the battery - either it's no good or it doesn't have enough power and needs to be charged- the starter coil (which can go bad and require replacement), or the starter itself.

To test for each of these, first put a meter or charge tester on the battery and be sure it has sufficient charge. If not, recharge or replace the battery.

Next, test the ignition or starter coil with a meter to be sure it is receiving and sending sufficient power. Be careful or have a professional do this, as it can be dangerous.

Finally, if the starter is bad, remove it from the vehicle and have it tested on a bench. It should crank at a specified RPM (rotation per minute) when given a specific charge of power. The RPMs/amp are different for each vehicle.

Most likely, if the battery and coil are OK, the starter has gone bad.

Engine starter and solenoid
Starter and solenoid

Grinding or Whining Noise

This indicates a bad starter or bad connection between the starter gears and the transmission. In the case of the former, you'll need to remove the starter and have it tested. You may see wear on the gears, which could indicate it's no longer connecting to the plate or is "skipping."

If that's the case, you're likely to hear grinding noises when you attempt to start the vehicle. In that situation, you could do permanent or costly damage to the starter and transmission if you continue to try to start the vehicle. Several culprits could be the cause of this bad connection.

The most likely is that the starter has come loose due to a loose bolt or a broken bell housing on the transmission.

Another problem could be a lack of lubrication causing excessive wear on the starter gears. Finally, the flex plate or gears (where the starter connects to the engine to start it) could be cracked or broken.

Alternator Repair Issues

The two most common issues with an alternator going bad are bad brushes and circuit failure. Both require that the alternator be tested to find the issue.

See our repair article on Alternators for more information.

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