My car would not turn on one day, I turn the ignition and it clicks,lights turn on. I thought I needed a new starter so I replaced it, it still would not turn on until I had someone jumpstart it. The next day it still wouldn't turn on. I've taken the battery to auto zone had it checked it and its fine 85% charged. So I cleaned around it even replaced the terminals, jumpstart it, turns on but then I had the check engine light on. Later that night it wouldn't start again unless I jumpstart the battery. Auto zone also checked my alternator and that was fine too. Can someone help me, tell me what you think it could be? Thanks.

 

The click when trying to start means flat battery (note that lights could still turn on)

Always put key in ignition position II when reconnecting/jumping the battery. Otherwise, this vehicle is prone to annoying electric faults due to a surcharge. Key in position II is as per official Volvo instructions.

Either the battery goes flat due to a short somewhere that drains the battery while the car is off, either the alternator is faulty and is not charging the battery.

For a short, check if any systems don't work properly - radiator fan, alarm siren, etc.

For the alternator, a garage could check the voltage while running and see if it's charging right or not.

 

Thanks, I had my Volvo taken to a Volvo dealership and they told me that it was the battery. They told me that it would be best to have a Volvo battery not just any, so they added one and its much better. One thing though is that when I turned the car on and changed the gear to drive, the engine jerked a little at first then it drove fine. I'm wondering, what could that be? I'm still a little worried.

 

It is a good idea to disconnect the battery (both terminals) for 12h to have the main computer reset. This can solve electrical gremlins. Don't forget to have the ignition key in position II both when removing and reconnecting the battery cables.