Skip the auto shop - Our mechanics make house calls

Q: Battery dead, car won't start

asked by on

Car won't start, just clicks when turn the key, jumped it and took to autozone to check battery, had 60% charge, brought home and let run for 30 minutes, next morning dead again, no lights left on, is it alternator?

My car has 84500 miles.
My car has an automatic transmission.

A: Hello. The best thing to do is have a batte...

Hello. The best thing to do is have a battery shop perform a "load test" on the battery. That is very standard procedure. The battery has to be in a fully charged state (they can do that, too) before such a test can be performed. If the battery fails a load test (if it’s 6 years old, it may very well fail or be "marginally" good) obviously you have to replace it. If it "passes", be sure to ask the Tech if it marginally passed. That is, batteries don’t last forever and at 6 years (if it is 6 years) you are going to have to replace it soon anyway. If it "marginally" passed the load test, absolutely replace it now to avoid getting stuck on the road.

Regardless of the outcome of the battery test, you need to test the output of your alternator. Once you have a functioning battery, attach a voltmeter to the positive and negative terminals of the battery (don’t short circuit anything as the battery could explode). While the car is running, you should see a volt reading on the meter somewhere in the range of 13.9 to 14.5 volts, however, you must check your Factory Service Manual for the exact specification for your car (which test protocol might also require that you maintain a certain engine RPM during the test).

The range of values for voltage are simply typical and so, for example, if you are reading 12.8 volts or something well below 13.9 you possibly have a faulty alternator OR a wiring problem like corrosion or loose terminals. Even a perfectly good alternator will not charge the battery and run vehicle electronics if, for example, the connections to the battery are in poor shape. If you need assistance, YourMechanic can evaluate both your battery and charging system, during a mobile visit right to your door, and get this issue fully resolved for you while answering any further questions or concerns that you might have.

Was this answer helpful?
Recommended services
Get a Quote

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: ive blown the center console 12v plug fuse installing led lights and now i cant seem to find the fuse dedicated to this outlet

Check the fuse 22 in the panel inside engine compartment.

Q: The glow plug goes turn on after driving for 10 minutes. When turning the engine on and off, it does not apear again.

Hi there. The glow plug light comes on when the computer is detecting an issue with the glow plugs to the engine. There are stored codes and pending codes. If the light goes out after turning the key off and...

Q: What could be the problem? My GTI 5 is showing these codes after diagnosing low pressure regulation, fuel pump circuit.

Hi there. If you are getting codes for the fuel pump circuit, then there could be a problem with the fuel pump, fuel pump relay, or the electrical wiring. First check the fuel pump relay and see if the relay...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.