Skip the auto shop - Our mechanics make house calls

Q: I can't figure out why my car won't turn over without a jump even though the battery is fully charged.

asked by on

My car runs very well except that it needs to be jumped in order to start the engine. As long as the cables are attached to the battery, it will turn over without hesitation.

Once running I can drive the car all day long but as soon as I take the key out, the car won't turn over again (I hear one weak whine and then nothing).

It has a new alternator and the new battery seems to be holding a nice charge as well. When the engine is off, the accessories all function properly (ie. lights are bright, radio is loud, ect). Everything except for the seat belt warning which will not turn off even when the seatbelt is properly engaged.

Any troubleshooting advice would be greatly appreciated!

-thanks-

My car has 60000 miles.
My car has an automatic transmission.

If the engine cranks fine as soon as you connect jumper cables then you most likely have corrosion on the inside of the battery clamps where they touch the battery post. You should disconnect each battery clamp and clean them. Your engine should now crank over fine. I would recommend having the battery and charging system tested to make sure it is charging good and any problems are addressed. The seat belt system will need to be diagnosed by a mechanic in person in order to properly diagnose the seat belt light stays on.

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
  • I can't figure out why my car won't turn over without a jump even though the battery is fully charged.

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: Fluctuating coolant readings

Hello. Your fluctuating coolant temperature may be caused by a cracked cylinder head or leaking head gasket. It sounds like you have replaced everything else that could be causing this issue. If the head is cracked or the head gasket...

Q: Can a vehicles paint finish get scratched from blowing dust/contaminates?

It is possible that debris, like small rocks, are being kicked up by other vehicles on the roadway and striking your vehicle causing scratches. Large trucks kick up more debris than small cars, so you could try avoid driving behind...

Q: My car shifts gears just fine but it hardly wants to take off and the rpms go up very high but hardly accelerates. 1994 Honda Civic

Hello - I believe you have a severely slipping clutch. Either the clutch is worn out, or the clutch disc is contaminated with engine/transmission oil, and is slipping for that reason. If the clutch has not been replaced with your...

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...
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...
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.