Do not ground anywhere but to battery if installing on a boat!
The directions could of been a little clearer on the power wiring. Not Only does the Yellow and Red need 12 volts but the blue wire as well for the remote. Also, this has to be grounded to the battery or metal. For a boat, never ground to your metal hull!!! This unit cannot just be connected to a fuse block. Power maybe... but you’ll run your battery down fast with other things connected, but no way can you ground to a fuse block. My suggestion is to run two 10 gauge wires to an independent battery source. The sound is great! I added two speakers and recessed mounted the remote. Everyone loves it and thinks I paid a lot more than I did.