Well went to start the car today and the battery was dead. Their was a very loud clicking/ticking sound coming from this box circled in red. What is it? Its grounded by a metal bar it attaches to, now their is very quiet ticking when attached. I need to replace the battery anyways, but just want to make sure its nothing else.
this isnt my engine, just for reference.

 

it's a solenoid. its supposed to click. your batt should just be low if it clicks but not cranks. charge it up

 

It's the headlight relay. If the headlights were on and the battery was very low it may click, but normally it shouldn't.

Paul