This series of articles will cover causes of a vehicle not starting and what checks and repairs the driver or owner can perform. Causes of a vehicle not starting can be very minor or very major. As this series of articles progresses, discussions of “no start” causes and repairs will begin with the less complex and will move on to the more complex. As this series continues, other areas of the vehicle may be discussed, such as brakes, suspension, steering, lighting, supplemental restraints, transmissions, emissions, and electrical systems.
A vehicle “no start” condition can be categorized into two situations. First, when the key is moved to the start position nothing happens, which in professional circles is referred to as a “no crank, no start” condition. This means that when the key is moved to the start position the engine does not rotate, spin, or turn over and also does not start. The second condition is referred to as “crank, no start”. This means that the engine does rotate, spin, or turn over, but does not start.
When a vehicle has a no crank no start condition, special attention is required while attempting to start the vehicle to determine whether any noises can be heard. These noises are most often clicking or chattering. The most common cause is loose or corroded terminals or electrical connections to the vehicle battery. Batteries have various types of terminals, but the most common are top post and side post. Top post batteries are susceptible to corrosion. Side post batteries are susceptible to loose terminals. Side terminals can feel tight but still may be loose enough to cause a no crank no start condition. When checking for loose battery terminals raise the vehicle hood and support the hood to prevent personal injury during an under-hood inspection or repair. Search for the battery. Most batteries are located in either the left front corner or right front corner of the engine compartment. The left or right side of a vehicle is determined from being seated behind the steering wheel. Look carefully because some batteries may be below other items in the engine compartment.
If the battery is not in the engine compartment, then it may be inside the left front wheel well or under the rear seat cushion. Access to the latter two locations may be beyond the ability of some drivers or owners. In this situation the vehicle should be towed to a professional. Once access to the battery is obtained, visually inspect the battery condition. Determine if the battery is top or side post. Attempt to twist the terminal attached to the post clockwise and then counterclockwise. If the terminals move then they will need to be tightened. Top post terminals will require a 13mm or 10mm combination wrench depending on the vehicle. Side post batteries will require an 8mm combination wrench.
Once the terminals have been tightened, attempt to start the vehicle. If it starts the repair has been successful. If the vehicle does not start then further inspection and diagnosis will be required, which will be discussed in the next and future articles.