It's important to check the quality of your jumper cables. Some jumper cables cannot carry sufficient current, especially those that are too long or too light. Low-quality jumper cables can be easily damaged and cause a jump-start to fail.
If jump starting gets your engine started and running, but the car will not start again once you turn it off, the battery is probably the problem. In this case, the alternator is doing its job of keeping the battery going once it has been jumped, but the battery can't hold a charge when the alternator is shut off.
If the car starts with jumper cables, then your battery or alternator is not working properly. Use a car battery tester that puts a load on the battery when testing it. Multimeters only measure open circuit voltages which can look okay even if the battery isn't.
Your car's ignition switch, alternator, battery, starter, or a fuse could be malfunctioning. Your safety switch could be broken. This switch keeps your transmission from starting unless you're in park or neutral. If it is malfunctioning, it will keep your car from starting.
If the battery is completely dead, it won't have enough power to turn over the engine, even with a jump start. In this case, you'll need to replace the battery to get your car running again. Another reason why a car battery won't jump is because there is a problem with the charging system.
An effective method to determine whether it's your battery or alternator that's gone bad is to connect jumper cables from a running vehicle's battery to yours. After a few moments, try starting your vehicle. Once it's started, remove the jumper cables — if your engine stalls, your alternator has probably gone bad.
It is possible in some cases to jumpstart a vehicle that has a faulty alternator, as long as the battery has enough of a charge to keep running. However, the alternator should be replaced as soon as possible.
When you attempt to start the vehicle, is there a clicking sound, but it won't turn over? That may be a good sign. If a jump gets the car running, but won't turn over again once it's shut off, a dead battery is likely the cause.
Can you jump-start a car with a bad starter? Most of the time, NO, you can't jumpstart a car with a bad starter unless you repair it. When the battery is dead, jumper wires or boosters are employed. You use a second battery to provide the necessary electricity to start the car.
You should leave jumper cables connected for around five minutes at first. If your car still doesn't start after five minutes, it may take longer—up to 30 minutes in extremely cold temperatures. If after 30 minutes your car still doesn't start, there's likely more wrong than simply a dead battery.
Can a car battery be “too dead” to jump-start? No, a car battery is never “too dead” to jump-start. If the jump-start doesn't work, you may have a faulty alternator or a dead battery that necessitates a replacement.
How Much a Starter Replacement Costs. The cost of rebuild parts for a starter can range from as little as $50 to as much as $350. A brand-new starter can range from $80 to over $350. For a qualified mechanic to replace or rebuild your starter, you can expect to pay between $150 and over $1,100.
How long should you leave the car running after a jump? It's best to drive the car around or let it idle for at least 30 minutes after you jump-start it. Ideally, you should drive the car around for 30 minutes to allow the alternator to charge the battery to a good level.
The Do Nots of the Alternator
Your car will just not start. Some people believe that you can just tap the alternator with a hammer to get it to operate. You should not do this because it will damage the part and you might even damage the surrounding parts to the car, resulting is a large car repair bill.
If you ever hear growling or whining noises coming from under the hood, you could have alternator problems, which should be checked out by a professional ASAP. This growling or whining sound happens when the belt that turns the alternator's pulley becomes misaligned or rubs against the side of the pulley.
Alternators can average anywhere from $100 to $350, depending on the model. In most cases, costs will average between $350−400 for the alternator replacement if no other parts need to be changed. Add another $20 to $50 to your bill if the serpentine belt has to be replaced as well.
Alternators can go bad suddenly, or slowly over time. If your alternator is slowly going bad over time there are some warning signs you can look out for.
Most alternators will last between 80,000 and 150,000 miles — or about seven years. However, your driving habits and the area where you live could wear it out prematurely.
If you have jump-started your car, it is recommended to let your vehicle run for at least 30 minutes because it would typically require at least half an hour to charge a dead battery entirely or at least sufficiently.
The battery will charge faster if you rev the engine faster. Why? Because the faster the crankshaft turns, the faster it turns the belt that runs the alternator. And the faster the alternator turns, the more electricity it produces to run all the electrical stuff in the car — and recharge the battery.