Hey I have an 04 civic SI, it came wired for subs. Whoever had wired it up must have done something wrong because all that’s worked was the drivers side door tweeter and got the door speaker working as well. There was 4 speakers wires lose as I tested them to the splitters off the amp I lost all power to the deck and amp, as well I lost the power door locks, the inside light when car is off and door is open and the security beeping when key was in.
all fuses are good.
Any suggestions will help. Thanks.

 

welcome to the forum. It would be better if you started from scratch. go to the source of the power and start from there. this will allow you to see where the previous owner might have crossed lines.