What’s the cause of clicking when key is turned and car doesn’t start

Hello, the clicking noise is are relays clicking due to a lack of needed power to turn then starter motor which turns the engine. This is most likely due to a battery that is low in electrical output -- either not enough voltage or amperage due to low charge or the inability to become fully charged. First, check your battery to determine if it is good or fails load testing. This will have to be professionally done. Second, once you have a known good battery installed in your vehicle that is fully charged, you can perform needed testing of the charging system, such as the alternator. Ensure proper recharging is occurring. In rare occasions, you could also have a starter motor concern or an internal engine problem -- but you'd probably have other symptoms for those. Don't jump to that conclusion; start with checking then battery and starting system first. www.repairpal.com/repair-shops