Newer Kenwood HUs have a protection circuit. If your speaker cables would be shorting, it would show PROTECT on the screen and shut down. That doesn't seem to be the case here.
There is a cell mute cable at the back of your HU. This is normally provided so you can connect it to an aftermarket handsfree kit, so when you get an incoming call your system automatically attenuates. In you case (I assume you don't have such a kit) this cable should not be connected to anything.
Check this cable. My guess is its touching ground or such, causing it to trigger attenuation. |