How to Diagnose a Loss of Spark in a Car Engine

You need your car to get to work, take the children to school and run your personal errands. It's a hopeless feeling when it fails to start. If you ever find yourself in this situation, there are a few things you can do to diagnose a loss of spark in your car engine.

Instructions

Difficulty: Moderately Easy

1. Examine the battery cables. If you try to turn the cables and one appears to be loose, you may have found your answer.
2. Determine whether there's corrosion on the end of the cables or on the battery terminals. Corrosion appears as a whitish, powdery substance. If you find that corrosion has started, brush it off with a wire brush.
3. Make sure your car is in park if your vehicle has an automatic transmission. Some older models may start in neutral, but new models only start in park.
4. Check for blown fuses. Fuses and relays protect electrical components, including the starter. The fuse panel is generally located under the dash. You can find the relay panel under the hood.
5. Remove the distributor cap. Ask a friend to crank the engine and notice whether it turns. If the distributor doesn't turn, you may have a broken timing belt or chain.
6. Check for power with a test light. Locate the power wire attached to the engine coil. Turn the ignition key on without cranking the engine. If power is present, the test light will light up. This means that the ignition switch is in good working condition; therefore, you still need to look for the problem.