It could also be that the alternator is bad or the belt is loose. If the alternator is not keeping the battery fully charged then it might be strong enough to start the car on warm days but not on cold days.
Places like Autozone will check the entire system for free.
Use a digital multimeter set to the 20 volt DC scale and check the output of the alternator at the battery with the engine running at idle. You should read from 13.5 to 15.5 volts. Any less and the alternator is defective.
I think you may have a low current drain somewhere. Check that your interior lights are shutting off, in trunk and under hood too. And the motor on your tape player isn't running when it shouldn't. I've seen that one a few times.
sounds like you have a bad earth on the lead to the battery the negative is normally the earth
Check your alternator
I bought a brand new battery a few weeks ago and my car was running fine until it started snowing yesterday. Now I need a jump whenever I try to start my car. My lights work but they are kind of dimmed when the car sits and when I'm driving it. Does anyone know what could help? Thanks.
