i just got a amp and a 12 inch sub installed and when i turn off my radio, not my key my sub just starts bassing like boooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooom and when i turn on my radio it stop and its normal please help!
make sure your ground, power and remote are all in the right places, i had a problem that was similar to that once and once i changed the wires, they worked fine.
unplug the rca wires from the amp and see it it stops. if it does then its probably an rca problem. If it doesn't stop then check the power and ground wiring. Then check the amp.