Won't start

[miablue]

Turn key, lights come on, radio, etc. & only get clicking noise.
After about 4-5 hours, I turn key again and car starts
Runs fine for 3 days & then I let it sit for 2.5 days.
Go to start the car, same thing, clicking noise under hood, all lights working, but it wont start.
Should I get a new batter or is this the starter or the alternator?

 

[KidVermicious]

What year? What engine?

Have the battery tested before you replace it. When it doesn't start, check the battery voltage. Then leave the key in the on position and try jumping the starter solenoid straight to the positive battery post. Report back.

 

[redbull9944]

Check to make sure that the connections to the battery are good and tight. Had the same problem after I installed some off road lights.