Skip the auto shop - Our mechanics make house calls

Q: Battery light

asked by on

I have a rebuilt transmission, new altinator and battery but when I start the car it starts right up. But when it's on the battery light comes on i dont know what else to do or what can be causing the light to still come on
My car has an automatic transmission.

A: Hello. This may be caused by a faulty groun...

Hello. This may be caused by a faulty ground connection or potentially a bad voltage regulator. Try checking to be sure you have a good connection from the battery to the car’s chassis (black negative battery cable from the battery to the chassis). The voltage regulator is a unit that is responsible for regulating the voltage charge from the alternator to the battery. When this is not working properly, it can undercharge or overcharge the battery causing the battery light to come on. I would recommend having an expert from YourMechanic come to your home to diagnose and test your voltage regulator.

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・Fair and transparent pricing

Get a quote

What others are asking

Q: ABS light on

There is a technical service bulletin (TSB) GM has put out concerning a bad ground to the electronic brake controller module or EBCM. This causes a loss of communication and sets the ABS light. There are fault codes associated with...

Q: My wiring in my headlight on my passenger side messed I was wondering from a mechanic point what's the price I was be looking at

Depending on how burnt the wires, this will control how much repairs will cost. Just to replace the connector end and replace the headlight bulb will be about an hour's worth of labor plus parts. In most cases the repairs...

Q: Fuse keeps blowing

The turn signals are powered in a couple different ways. The brake light fuse and the turn fuse. If either are blown then you will have issues of no turn signal or turn signal stops when you push on the...

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...
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...