Trouble shooting
How To Test a Circuit Using a Test Light
A circuit tester is an important troubleshooting tool when you are trying to diagnose an electrical problem. You need to know what wire does what and which wires are active before you start. You can also use a test light to check for good ground or ground faults

Troubleshooting Through the Exhaust Pipe
Your exhaust pipe has smoke coming out of it. What color is the smoke? What does blue smoke mean? White smoke? Your exhaust tells a story of what's going on inside your engine. You can use your exhaust smoke color to troubleshoot your engine's health.

How To Check Your Coolant Mixture Percentage
Keeping a proper coolant mixture is vital to your car's health. Antifreeze should be close to 50 percent mixture. You can test your coolant mixture easily with an inexpensive coolant mixture tester that can be bought at any auto parts store.

Testing an Ignition Coil on the Car
If you're getting no spark at your spark plugs, you might have a bad ignition coil. The ignition coil sends the spark to the distributor, which then sends the sparks out to the spark plugs. A bad coil means no spark, so testing your ignition coil is an important step in troubleshooting an no-start or a no-spark issue.

Bench Testing Your Ignition Coil
Your ignition coil can be the culprit in many automotive troubleshooting situations. You will need to test your coil to see if its bad. On-car testing can evaluate, but for a definitive idea of whether you have a bad coil, you need to perform a coil resistance test. This type of coil testing can tell you if your coil is on the way to being bad even before it is obvious.