whining through speakers odd

I used to have a jensen flipout in my truck(05 titan) with one preamp going to a sony 600 watt peak amp for my 6x9s and the sub output going to a kicker 750 pushing to cvrs. I sold the jensen to a friend and put my old jvc in for the time being. Now I have a whining that follows the engines rpms that I didn't have with the jensen. The JVC on only has one preamp which I connected y rca connectors to to get 2 rca wires out. The JVC was in another friends car before and there was no whining. The power wires and rca wires arent run together, the radio swap seems to have caused the problem but I don't know how. Any ideas?Jensen VM9214 Flip out, JVC 6x9's,Sony 6x9's Pioneer 6x9's, 2 Alpine Type R's in ported box, JL 1000/1 V2 Slash, Sony GTX6040 240 watt amp, Kicker CVR(Black), Alpine 500 (300) watt amp.

def by 20 wrote: I used to have a jensen flipout in my truck(05 titan) with one preamp going to a sony 600 watt peak amp for my 6x9s and the sub output going to a kicker 750 pushing to cvrs. I sold the jensen to a friend and put my old jvc in for the time being. Now I have a whining that follows the engines rpms that I didn't have with the jensen. The JVC on only has one preamp which I connected y rca connectors to to get 2 rca wires out. The JVC was in another friends car before and there was no whining. The power wires and rca wires arent run together, the radio swap seems to have caused the problem but I don't know how. Any ideas?

I had this problem in my car. it came with a old kenwood, sounded great so i added a amp. few months go by it starts whining/pulsing in the sub. then whines/pulsing through out every speaker in my car even the door (not connected to the amp)  i nopitced when i touched the rca's it would stop. ended up being a loose connection inside the radio

^Cliff notes in bold.