Ok I have read all kinds of threads on engine whining and still cant figure this out. I will try to be descriptive as possible. I have a 2007 Mitsubishi Galant the specific one I have did not come with a factory amp but there is a wire for one under the driver side dash with a 40 amp fuse in the fuse box. I hooked a wire to it and ran it down the center of the car under the carpet to the amp inside the trunk. I did the same with the remote wire from the head unit. The ground is ran to a bolt underneath the back seat. This amp is for my two 6x9s in the trunk. I unhooked the speaker wire from the 6x9s and ran them to the amp high input then out the amp back to the 6x9s. Now I have engine noise in the 6x9s. I have troubleshooted all kinds of things and this is what I have found. I have unplugged the speaker wires that run from the head unit to the high input of the amp. The amp is still powered and the 6x9s are still hooked to the output of the amp. The engine noise is gone now. It seems to me that the noise is coming from the speaker wires that run from the head unit to the amp, so I suspected that the head unit was injecting the noise on the speaker wires. I hooked up the speaker wires back to the amp high input but left them unhooked from the head unit and I have the noise again. So it cant be the head unit. What gives???
have you tried a line output converter that converts the speaker wire into RCA jacks? it could possibly have something to do with the speaker inputs on the amplifier. Im not sure man, i haven't ever messed with hooking up amps with a speaker input.
