Skip the auto shop - Our mechanics make house calls

Q: We just putting in a brand new battery and alternator and last for the week battery now it won't hold a charge

asked by on

I put in a new alternator and battery car lasted a week now the battery is dead again what could be the problem
My car has an automatic transmission.

Several issue may be causing the battery to not charge or not hold a charge. The first and easiest step is to trace the wiring circuit involved with the starting system, and visually inspect it for any physical damage.

All of the connections need to be clean, dry, and tight. The conduit needs to be flawless and with no breaks or cracks. These flaws can allow moisture in and corrosion to form. A bad connection may have been jostled enough during installation to make a connection temporarily.

As long as the battery and the alternator were replaced together, the issues are likely wiring-related. Otherwise you may be looking at a bad alternator ruining the new battery.

If the starting system seems flawless, you may be experiencing a parasitic draw on the battery. These can be caused by aftermarket parts, radios, security systems, or any component that requires a memory for a setting. You can likely test for a draw with a proper scan tool.

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!
  • Home
  • Questions
  • We just putting in a brand new battery and alternator and last for the week battery now it won't hold a charge

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: what would be the problem if the car starts and fail to move either forward or reverse and it revves itself when started?

Hello. If the van was moving fine prior to the wrong oil being put into the transmission then you may have a transmission failure. It the correct transmission fluid was not used then it can cause some serious internal transmission...

Q: My battery lost power and I recharged it. Now, every time I hit my breaks all of my lights blink for one minute.

Hi. This sounds like the battery terminals are either loose or going bad creating a bad connection with the battery. There also could be corrosion on the terminals causing a bad connection with battery. The battery supports may not be...

Q: I am having trouble finding an oil pan gasket for this vehicle.

The lower oil pan on your Pontiac Sunfire does not use a gasket but a 2mm bead of silicone sealer all the way around. Do not over apply sealer or you will cause sealer to get caught in oil pick...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...
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.