Q: I have a 2007 300 and if I get a jump it will start most of the time and later will need a jump again to start

asked by on October 01, 2017

My car won't start without a jump then after I turn it off I have to get another jump but sometimes it won't start is it battery starter or alternator
My car has an automatic transmission.

Battery Replacement $232.05 - $347.15 Get a Quote
Alternator Replacement $151.62 - $1237.14 Get a Quote

I would start with having the battery load tested to see if the battery needs to be replaced. If the battery is good, I would then suggest having the alternator checked to determine if it is receiving the proper amount of voltage from something called the voltage regulator. The voltage regulator regulates the charging voltage that the alternator produces, keeping it between 13.5 and 14.5 volts to protect the electrical components throughout the vehicle. The voltage regulator controls the field current applied to the spinning rotor inside the alternator. When there is no current applied to the field, there is no voltage produced from the alternator. When voltage drops below 13.5 volts, the regulator will apply current to the field and the alternator will start charging. When the voltage exceeds 14.5 volts, the regulator will stop supplying voltage to the field and the alternator will stop charging. This is how voltage output from the alternator is regulated. When the voltage regulator is not working properly, this may cause the alternator to allow the power the alternator supplies to drop resulting in the battery dying again. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle.

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

2008 Ford Edge turned key on key off key on and displayed check brake system and went off but able to replicate every time

At key on, many dash warning lights will come on momentarily, and then turn off, as a system test as well as bulb check. If the brake warning light goes off immediately, that is normal. If you suspect a fault...

What does the car do when anti theft is activated? does it have no compression kind of like head gasket?

The head gasket and/or other mechanical components of the engine are NOT involved in this fault you are experiencing, at all. Cavaliers have quite a few electrical and instrument panel problems. If you search the NHTSA database for complaints from...

Where is the body control module located on my pickup?

The BCM is under the center console up near the front near dash. One of the seats need to be removed first, then you will need to remove center console. Once the console is removed you can then access the...

Clutch release bearing gone

The bearing will have to be replaced. I recommend having a reputable transmission handle this repair. I also suggest having the clutch and pressure plate replaced while they are in there. 

Car has a hard time starting

Hello! On your particular vehicle, the hard start condition is commonly caused by a faulty fuel pump relay, fuel pump, or fuel filter, so I suggest checking the fuel pressure to determine if there is a problem with the fuel...

Detecting strong gas smell.

The EVAP system is used to prevent fuel vapors from escaping into the atmosphere. The powertrain control module (PCM) monitors this system to ensure it is completely sealed. If a leak is detected, the PCM will illuminate the check engine...

Related articles

2012 Chrysler 200 vs. 2012 Chevrolet Malibu: Which One Should I Buy?
When you are looking for a small-range sedan, you need to get somewhere quickly and inexpensively, and may even need to take a few kids with you. Slightly larger than a commuter car, these mid-size options offer decent gas mileage,...
A Buyer’s Guide to the 2012 Dodge Ram
While While Chrysler has decided to give Ram its very own division, it seems impossible not to think of the Ram 1500 as a Dodge. After all, you’ll still buy your 2012 Ram at a Dodge dealer, and it remains...
The Best Used Cars to Buy If You’re an Interior Designer
As As an interior designer, you need to transport a great many different items, including fabric, paint and wallpaper samples and sometimes even furniture items. You probably don’t handle overly large loads very often, and when you have to, you’ll...