capacitor led problem bad cap?

Hello I got my 3.5 farad capacitor installed charged and all and next day i went to the trunk and looked at my cap seems normal so i turned on car, and my cap is beeping i go to the back and check the the volt LED and it was going from 10 volts lowering it self till it reached 9 or so then it started to go up stayed in 10 or so beep stopped so i assumed it was just charging back up at this point the cap was the only thing plugged in no amplifiers etc, left it alone later on that day i started installing the wires for the amplifier and i noticed that the ring terminal on the negative of the cap was a bit loose, so i decided to push it in a little. a spark came out my LED lights turned on the bright blue LED turned on volt meter didnt really read anything just some numbers that didnt have all the sticks to complete 1 number i removed the ground and it stayed like that for a while until it shut of the spark came from just connecting the ground to the ground on the capacitor, and now that i have my amp installed with the cap and all i have no blue LED on the cap no volts reading from the LEDS on the cap my remote wire is set i tested all with volt reader etc is my cap bad now? i just got it yesterday -_-' please help anyone

Yep, probably a faulty cap (if you are talking about its heavy connector). And they don't discharge & recharge for no reason. But don't bother replacing it. You'll see plenty of threads & reply hereon as to why not (and a few for when they are desirable) and superior solutions. If you bought it new, get your money refunded.

Use a volt meter, and if the capacitor has 12 volts across it, and it does not light up, then yes it is faulty.

thank you ill return it monday getting a battery

And get a battery isolator (a relay of you can use the charge light).