Q: New alternator, car not starting in the cold

asked by on December 27, 2017

As the weather started getting cold this winter my car started stalling out, but once it warmed up it ran fine for the rest of the day. Then we had one severe cold day and it wouldn’t even start. My friend and I jumped it and I took it to WalMart to have them test the battery. He said the battery was fine but it wasn't receiving a charge so he thought it might be the alternator. I spoke with a few mechanics and everyone agreed. So yesterday, it won’t start again in single digit temperatures, and I change the alternator. It started after a jump and we let it run for a while. After it sat off for about six hours in negative wind chill I tried again and it started fine. Then it sits overnight and this morning it won’t start again. Is it possible that I just didn’t charge the battery long enough? Or are we looking at a completely different problem? Side note...I’m trying hard to not put a lot of money into this car and I only need it to last a few more months. Thanks!

My car has 180000 miles.
My car has an automatic transmission.

As you may know, cold weather is extremely tough on batteries. Depending on the strength of the charge, you may not have charged the battery sufficient to a point for it to hold a charge. Generally, for a battery to charge significantly, it will need to run for 30 minutes to an hour for the alternator to properly charge it. The other possibility may be that you could have a failing voltage regulator, which is the unit that monitors the charging of the battery by the alternator. If this is not working properly, the alternator will not properly charge the battery. I would recommend having an expert 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

How does the satellite radio work?
If your car is equipped with satellite radio, your audio system is set up from the factor for SIRIUS Radio. After you have paid for your subscription, you will be able to listen to satellite radio wherever you are (barring...
Power steering fluid leaks
The steering gear leaking is best serviced by replacing it with a new or remanufactured unit. The hoses should be checked also. I recommend you have a mechanic like one from YourMechanic inspect your vehicle for power steering leaks (https://www.yourmechanic.com/services/power-steering-fluid-is-leaking-inspection)....
my rpms remain around 2500 rather than dropping down to the normal 500-1000 idle speed
An intake manifold vacuum leak is likely the issue with your VW. Have a close look at all vacuum hoses that connect to the intake manifold. The large hose that connects to the brake booster is a suspect. Listen closely...
Car shakes and pulls to the right
Greetings. The Mercury Mystique's shake that you are experiencing could be due to an abnormally worn tire or a worn motor mount bushing. An abnormally worn tire could cause a shake and a pull. I suggest that the tire is...
Running rough 2002 Ford Focus
Hi - rough running (https://www.yourmechanic.com/question/car-runs-rough) can be caused by a number of things: misfiring, dirty throttle body, injectors, fuel filter, idle air control valve and so on. There was a technical service bulletin from Ford for this engine which pointed...
cold start issues
Hi Jim. The poor cold start may be related to a faulty/dirty IAC (idle air control) valve (https://www.yourmechanic.com/services/idle-control-valve-replacement) not allowing engine RPM (revolutions per minute) to increase with ambient temperatures below 30 degrees. Assuming the check engine light is on...
Can you put spark plugs and fuel injectors from a 1998 4.6L Expedition into a 2001 4.6L Expedition? (an auto parts store associate told me I could)
The spark plugs will not make any difference with the engine performance, however, the fuel injectors are different and will cause the computer to not operate the injectors properly. This is why the engine light came on with all of...
Plate and dash lights wont turn off
I don't believe the 1996 car was using a lighting module yet, so you're in luck, all you are likely to need is a headlight switch replacement. Later cars used a lighting control module that made things way more complicated....
Recently replaced engine due to water damage. Now car shakes at idle and check engine light flashes.
If your catalyst is bad then I would suggest replacing it first and then clear codes and see how engine runs afterwards and if it needs further diagnosis.

Related articles

The Best Used Cars to Buy If You're a Gardener or Landscape Architect
Gardeners Gardeners and landscape architects need to haul around quite a bit of gear. As a gardener, chances are you will need to transport a variety of mowing equipment, along with smaller implements. You may also need to move shrubs,...
How to Get Ford Dealership Certified
Ford car dealerships offer automotive technician jobs to mechanics who are certified through either the ASSET or the FACT program.
Top 10 Best-Selling Cars of 2016
Ford F-series pickup trucks, Toyota Camry, and Honda Civic are some of the best-selling cars of 2016 and all deliver on reliability and efficiency.