Skip the auto shop - Our mechanics make house calls

Q: Changed battery car won't start

asked by on

Help! I took the battery out of my car. I put it back, all connections are tight. Keyless start wouldn't work. Used the key. Turned it on and some of the lights on the dash were flashing. The drivers side window rolled down but no auto function. Passenger side wouldn't work at all. Turned the car off and tried to turn it back on and now it won't start

My car has 84000 miles.

See if any diagnostic trouble codes were set via the OBD-II on board diagnostics. Prior to performing diagnostics be sure you have a fully, 100% charged battery. Confirm that the engine immobilizer system (security system) is not activated thus preventing the car from starting. If the immobilizer system is on, you may see a security warning light. If the warning light is on, to temporarily override the immobilizer system, see these instructions. If there is no starter motor operation at all, that is if there is no starter operation with the key held in the "start" position, the procedure is to test for power to the starter motor. If there is no power, then the electrical circuit supplying the motor has a fault (or, somehow the immobilizer system is on). That circuit begins at the battery and includes grounds, wiring (some of which is very heavy cabling), fuses, relays, the ignition switch and terminations. Basically, with a fully charged battery, and with the key held in the "start" position, the starter is either getting power or it isn’t. With the key in the "start" position, if the starter motor is getting power but the starter doesn’t work, then the starter is condemned and replaced. Note that starters can and sometimes do develop intermittent faults due to bad spots on the armature. The bottom line is if there is battery voltage to the starter (and no excessive voltage drop) and yet the starter doesn’t work, it’s dead. If you desire that a certified mechanic resolve this, please request a no start diagnostic and the responding certified mechanic will get the problem diagnosed and repaired for you. Please let us know if you have further concerns or questions as we are always here to help you.

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: 1999 c230 wont go into any gear and grinding noise when putting into park

The transmission needs to be overhauled or replaced. The internal main final drive gears are broken causing no gear engagement. Have the transmission replaced and or repaired and overhauled.

Q: Replace exhaust system

Hello there. The muffler is not a part that is typically replaced on your 2008 Jeep Grand Cherokee. Normally the muffler will last the life of the vehicle unless it is damaged or rusts. I am unsure of your meaning...

Q: after brake serviced 4 discs and all pads fitted, all wheels heat up a lot, higher petrol intake, no change after 150 km driven.

Hello David, thank you for writing in. The symptoms you are having all point to an issue with the brakes sticking or applying when they should not be. Heat is caused by resistance, and the pads are designed to create...

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...
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.