Any advice on why I have a new electrical whine from my sub amp?

The problem just started and I have not modified the system. The whine happens with the engine running and when the fuel pump primes at key on.

Whine disappears when RCA cable is unplugged from eq or amp. I also tried a jumper RCA from the eq to the amp and the noise was still there.

Any suggestions on where to start?

Thanks!