I am having noise issues when I start my truck and whenever I change tracks on my HU. I have a Kenwood KDC-X891 and whenever I start my truck I have like a humming, pulsing noise through my subs, and whenever I change tracks I get a little thump through my subs. However, this only happens whenever I am playing a CD. Whenever I am changing radio stations I do not have any noise, and if I start my truck with the radio on there is no noise. I do not have any noise whenever I use the USB port either. I can hook up a flash drive and flip through all those tracks without one thump and start my truck with it in this function without any noise, but once I switch the source to CD, while the radio is reading the CD, it has that pulsing, humming noise coming from the subs, and if I change the track while listening to a CD I get a thump through my subs. Why do I have these noise issues when the source is on CD. I can listen to the radio and my USB noise free but once I switch to CD it makes noise, it is only while the CD is reading, when the music starts to play the noise goes away, and when I change tracks. I also have a turn off thump but that happens in all sources and that is tolerable. What can I do to make it so that I do not have noise while listening to a CD? Sorry for the long post.

Remove the RCAs from the amp, noise still around?

when i remove the rcas or disconnect the subs the noise goes away. I believe it is a problem with the HU.

Me too. Try a direct ground to the battery.