Skip the auto shop - Our mechanics make house calls

Q: We have charged both batteries 100%, replaced the voltage regulator and altenator, but when we use the lights the battery drains

asked by on

What could cause the battery to continue to drain?

The last suggestion received was possibly a altenator fuse or the altenator we just replaced was bad.

My car has 90000 miles.
My car has an automatic transmission.

A: Hi, thanks for writing in. It sounds like t...

Hi, thanks for writing in. It sounds like the wire from the batteries to the alternator could be faulty. If this wire is not performing as it should the voltage from the alternator will never reach the batteries to charge them. I would recommend checking this wire for corrosion or damaged insulation. If you're uncomfortable or unsure of what to check I would recommend having this performed by a professional. If any damages exist to the wiring from the battery to the alternator I would recommend having that issue resolved in order to maintain a working charging system. Here at YourMechanic, we can have a technician come to your home or office to inspect and diagnose this issue for you, and make or suggest the necessary repairs.

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

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: my battery keeps going dead with a new alternator and new battery

Hello, thanks for writing in about your Oldsmobile 98. You need to have the charging system checked to see if the alternator is charging the battery. You may have a blown main fuse if the alternator is proven to be...

Q: Car Not Starting - 2013 Dodge Charger

Hey there. I would start with testing your battery and alternator with a multi-meter. Good batteries hold a charge of 12.6 volts or higher. If the battery is low, try to jump start it. If this starts your vehicle, test...

Q: No reverse light or horn - 1982 Chevrolet C30

Check the reverse light switch (located on the transmission?) to be sure it is closing the circuit when Reverse is selected. Make sure there is power to the switch, throught the switch, then power to the reverse light bulbs. Check...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...