Skip the auto shop - Our mechanics make house calls

Q: Changed battery twice in 2 weeks, I go to turn on and car is completely dead not even the lights work, what could it be? 2000 Acura TL

asked by on

I just got my car back friday after having the transmission fixed and noticed it making weird sounds like its idling weird and last week battery was completely dead not even lights worked and now again today I went to turn on the car and nothing! no lights the locks didn't even work and I didnt drive it all weekend. Why would it keep dying like that?

My car has 200000 miles.
My car has an automatic transmission.

A: Hi there - a repeating "dead battery&q...

Hi there - a repeating "dead battery" scenario has a couple of possibilities. One possibility is a bad alternator that is not charging properly. With the engine running, the system voltage should be close to 14 volts if the alternator is charging correctly. The second possibility is that something is draining the battery when the car is turned off. This problem can be diagnosed by connecting an ammeter to the positive (red) battery cable, observe the current drain (likely less than 1 amp), then, one at a time, remove each fuse, check to see if the current drain has dropped to near 0, then reinsert the fuse. This process should identify the faulty circuit in most cases. A professional mechanic, like YourMechanic, can perform this diagnostic procedure for you, and replace/repair the failing component.

Was this answer helpful?

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・Save up to 30%

Get a quote

What others are asking

Q: Making noise when hooking battery cables up.

Hi there. Assuming this was not an issue prior to the radio installation. This would lead me to believe you have inadvertently tied into the starter solenoid signal wire with the installation of the radio. Using a test light, probe...

Q: 105k miles on the chassis AWD model Starting Issues

I would verify that the battery is fully charged and that the terminals are clean and tight. I have seen people forget to remove the plastic protective cap on the battery terminals, too. Corrosion on the cable ends or battery...

Q: Battery/Car Not Starting

It sounds like your new battery may not be charging sufficiently due to a failing alternator that may not be charging properly. As you may know, the alternator is responsible for charging the battery while the engine runs by generating...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...