How do I Troubleshoot a Car That Won't Start Even With a Jump Start?by Dwight Malone
The steps for troubleshooting your vehicle's inability to start, even after attempting to jump-start it, are the same regardless of your vehicle's year, make and model. While your vehicle will usually start up without any problems when jump starting it, there are some instances where it will not and further investigation into the problem will be required. By following a few simple steps, you should be able to get the vehicle started and prevent having it towed to your mechanic. However, there are some instances where further repairs will be required in order to get the vehicle back on the road.
Troubleshooting the Jump-Start
Let the dead battery on the vehicle that is being jumped charge for a few minutes while the jumper cables are connected. In cases where the battery is extremely weak, trying to start the vehicle immediately after connecting the cables may not provide enough energy to start the car. By allowing the dead battery to charge up, you increase the chances the vehicle will start.
Check the jumper cables to see if the protective rubber coating is warm. If so, this is a sign there is increased resistance in the cables and enough current is not properly flowing to the dead battery. Try jumping the vehicle with a different set of cables.
Inspect the output terminals on the batteries of both cars. If there is a chalky white or green substance on the battery, there is corrosion present and is restricting the flow of current. Disconnect the jumper cables and then scrape off any corrosion. Reconnect the cables and attempt to start the vehicle again.
Non-Battery Related Issues
Verify that there is fuel in the vehicle. Even if the gauge indicates there is fuel, the gauge may have an electrical malfunction and the tank may actually be empty. Add a gallon of fuel and attempt to start the vehicle again.
Check the fuel filter to see if it is clogged and restricting fuel flow. Remove the fuel filter and see if it passes air through it. If it does, the filter is not clogged. The location and removal instructions vary by vehicle, so consult your owner's manual.
Check to see if you have worn spark plugs, which will prevent your car from running smoothly, or in some cases, prevent it from starting at all. Remove the spark plugs and inspect the tips. If there is fuel or black carbon build-up on the tips, they are worn and should be replaced.
- If your vehicle still won't start after taking the above steps, you most likely have a bad alternator, starter or electronic ignition, which will need to be replaced. The process for doing this varies greatly, depending on your specific vehicle.
- Car batteries should be tested annually to see if they are maintaining a proper charge. Having the battery tested will help prevent being stranded with a dead battery. Most auto parts stores will test batteries for free.
Things You'll Need
- Jumper cables
- If the outside temperature is below freezing and you suspect your battery is also frozen, do not attempt to jump-start the car. Jump-starting a frozen battery is dangerous and can cause the battery to explode.
Dwight Malone is a journalist who has worked for various Chicago-area newspapers, including the "Chicago Tribune" and "Naperville Sun." He has been a writer, editor and graphic designer since 2000. Malone studied journalism at Eastern Illinois University.