A couple of weeks back, my brother installed subs in his 2003 Accord. But suddenly all the subs stopped working. I have checked the remote wire, ground, fuse and they all were working fine. The amp seems to be working fine, I mean the light comes on and everything.. I never had problems with my amp or sub before.
Anyone knows whats wrong?

 

Take a voltmeter and check the power before the amp, and then check the line from the amp to the sub. If both are getting current... You might have a fried sub. I'm sure t00fatt will have input as well.

 

If the amp is turning on and not going into protection mode. First thing I would check would be the RCA's, make sure they didn't come loose at the HU. If you have another amp that is working try swapping the RCA's around. If you know your getting an audio signal but the sub still won't play then it's possible the wiring in the box came loose, or you burnt a coil and it's not shorting out. Easy way to check that is measure the impedance at the terminals on the box, should be 2 to 4 ohms depending on the sub. If it reads infinite than something is loose or burnt.