Malfunctions can occur not only as a result of a sudden breakdown, but also due to the accumulation of damage over time. Serious malfunctions are usually preceded by characteristic signs hundreds or even thousands of kilometers before the breakdown. Those components that sometimes break down without warning are usually small and fit easily in the trunk.
When any malfunction occurs, the first step is to decide where to start looking. Sometimes it's obvious, other times it's not. An owner who does not really think about half a dozen adjustments or replacements may be lucky and a malfunction (or her symptoms) will be lost, but he will not know what to do if the malfunction occurs again and may spend more time and money than necessary. A calm and logical approach will cost less in the long run. Always take note of any signs of abnormal operation that may have been noticed in the period leading up to the failure - loss of power, high or low gauge readings, unusual odors, etc. - and remember that the failure of parts such as fuses or spark plugs can only be the result of basic malfunctions.
These pages contain recommendations to help you troubleshoot the most common problems that may occur while operating your vehicle. These faults and their possible causes are grouped under headings referring to different components or systems of the vehicle such as the engine, cooling system, etc. Possible causes of malfunctions are indicated in brackets by chapters and sections that contain a description of the corresponding repair procedures. When troubleshooting and troubleshooting, the following basic principles apply.
Check for a malfunction. You must know exactly what the symptoms of a malfunction are before you begin work. This is especially important if you are helping troubleshoot someone who may not have described the problem very accurately.
Don't miss the obvious. For example, if the car will not start, make sure there is gasoline in the tank? (Do not rely on anyone's words and do not trust the fuel indicator!) If there is a problem with the electrical circuit, look for a loose connection or broken wire before removing the tester.
Treat the disease, not the symptoms. Replacing a dead battery with a fully charged one will relieve you of the problem for a while, but if you do not find the cause of the discharge, the new battery will soon also become discharged. Similarly, replacing oil-contaminated spark plugs will allow you to continue driving, but remember that the cause for contamination (unless it was the wrong type of spark plug) remained and it must be installed and eliminated.
Don't take anything for granted. Especially, don't forget that "new" component may be defective initially (especially if it's been lying in the trunk for months) and don't bypass components in the troubleshooting sequence just because they are new or recently installed. When you finally discover the source of a difficult problem, you will probably realize that everything was obvious from the very beginning.