Car problem diagnosis: When a car turns over slowly during starting and it wont start, the first thing to check is the battery.
How to check if the battery is the one causing a car won’t start
1) Turn on your car head lights.
2) Start the car engine while the headlights were on.
3) Observed the headlights brightness if there are changes during starting.
4) If there is change in the headlights brightness this means that the problem is battery related. If not then it is cause by another problem.
Now, you’ll have to check what the problem with your car battery is by doing the following.
1) Open the hood of your car.
2) Check the battery terminal look if there is corrosion on the terminals. This look like a white cruddy substance that is presence on the cable end and on the top of the terminals.
3) If there is a presence of this substance then this restricts the flow of the current into the starter making the car wont start. However, if the substance is not present then this means that the problem is a week battery.
Auto diagnose caused: Corroded Battery Terminal or Weak Battery
All about auto zone advice: If the problem is the corroded battery terminals, do the following.
1) Clean the terminals using a wire brush, apply baking soda and water on the terminals while cleaning with brush to help dissolve the corrosion.
2) Once the terminal is cleaned, apply petroleum jelly on the terminals to help prevents future formation of corrosion in the future.
3) Ensure that both battery terminals are coated with petroleum jelly.
However, if the problem is a weak battery do the following.
1) Open the battery fluid filler cap and check the fluid level
2) The fluid level should cover the top of the plates, if not then add distilled water just enough to cover the plates.
3) Bring your car battery to any battery shop and have it check if it needs to be re-charged or replaced.
If your car won’t start happens on a very cold temperature then the problem is that the battery electrolytes freezes up, check this article to know more Car Wont Start When Temperature is cold.