Okay I took out a subwoofer two days ago and now my car is showing a check engine light and a vsc light. Im guessing that the vsc is from the check engine light being on. But while i drive it im getting other light to come on light passenger seat belt light ac going out and power steering. Come to find out that the alternator was not charging the battery and the battery keeps dying. Couple things, I have checked all the small fuses in the car none are blown to what I can see, and when We were changing out the power cored of the speaker we lost the nut that holds down the alternator cable to the the hot side of the battery so we changed out the bolt and nut. My question is can that bolt be playing a part or how what should i check. I need some direction because i suck at electrical stuff and I dont want to have to replace the alternator if it is something else.

 

simple as this, have the system checked - many places will do it for free...

the bolt / nut will not cause any issues so long as it is all metal touching metal, is a good clean connection and is tight

 

If your getting a CEL pull the codes. The CEL will not come on for a failing alternator. If you don't have a OBDII reader go to autozone or any other auto parts store and they will read the codes for you for free. This is where you start with the trouble shoot. Good luck