Sounds from rear speaker that occur even if radio is turned off

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! It sounds like your MKC is experiencing some kind of electrical feedback or grounding issue. If sounds are coming from the rear speakers even with the radio off, it suggests that the audio system might be picking up noise from other electrical components—think of it like a party crasher at a quiet gathering! This can happen if there's a problem with the amplifier or if there's interference in the wiring, possibly due to a poor ground connection. Since you've already tried turning off the sound system and reconnecting the battery, I recommend checking the wiring connections for any corrosion or loose connections, especially at the speakers and the amplifier. If that doesn't resolve it, a visit to a qualified technician who can dive into the audio system's diagnostics might be in order. If you need any further advice or want help finding a trusted RepairPal shop in your area, please feel free to call us at 877-913-1554.