Skip the auto shop - Our mechanics make house calls

Q: I put a new battery in my van went to crank it up and its completely dead. Do i need a new alternator?

asked by on

i bought a new battery because the old one was draining so much. i put a new battery in the van and went to crank it yesterday and it was dead.

My car has 111749 miles.
My car has an automatic transmission.

A: This may be a sign of a failing voltage reg...

This may be a sign of a failing voltage regulator, a failing alternator or possibly a bad ground connection. As you may know, the alternator is responsible for charging the battery while the engine runs by generating amperage and recharging the battery while the engine turns the alternator. The voltage regulator is a unit that regulates the charging of the battery by the alternator. Often times this will result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. In either case, I would recommend having an expert from YourMechanic come to your location to diagnose your vehicle’s charging system.

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・Fair and transparent pricing

Get a quote

What others are asking

Q: I was driving home and came to a stop light and it just stalled and refuse to start.

From what you've described, there may be a piece of carbon lodged in the EGR valve. This can cause a stall and hard start conditions. This accounts for the vehicle having fuel pressure and spark still. Try to see if...

Q: Why when the front brake pads are installed onto the rotor they sit about a 1/4 of an inch higher than the rotor?

Hello. If you are referring to the brake pads extending past the edge of the rotor, then I believe you may have the wrong brake pads, or perhaps the wrong rotors installed on the vehicle. I would verify that the...

Q: Truck running very bad and I have a loss of electrical power.

Hi there. Before you decide to charge or replace the battery, check for a parasitic draw. To do this, remove the negative (-) battery cable from the battery and put a digital volt ohm meter (DVOM) on the battery cable...

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...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.