i have a rockford fosgate 250a2 amp and a JL12W3. i had everything set up in the car and it was working fine then one day the sub stopped working. the amp turns on (the red LED is on) but the sub doesnt work, like its not getting any power. i know the sub isnt blown because i hooked up my friends sub to my amp and that didnt work either. ive tried to figure out what the problem is but i cant figure it out. anyone have any ideas?

 

I had a similar problem when I got my amp. I tried everything that I could think of, but just couldn't get it to work. So I sent it back, and got another one. The second works just fine now.

 

you hooked up your friend's sub to your amp and it didnt work either?
That seems to be your problem if im understanding you correctly.

The amp...get it checked