Need Help with New Radio in Boat

[countryhick]

I have a 93 Stratos and I replaced the radio a couple of months ago. I turned it on in the garage for a while and it seemed to work fine, but when I took it out and after running for a while it got real hot on the back and quit. When I got it home, I checked the wiring and found the inline fuse holder had gotten pretty hot and deformed a little but the fuse was not blown. It was 10 amp fuse. The 15 amp fuse in the back of the radio was not blown either. I thought the fuse holder might have had a bad connection in it, so I replace the fuse holder and fuse. Turned the radio on and, again, it seemed to work fine. Took the boat out this weekend and the radio quit again. I haven't checked the fuses yet, but I know the back of the radio got real hot again. I used all the wiring from the stock radio (tape player) which was working with no problems. The stock radio did not have a remote wire, so I have the power wire and remote wire run together to the battery with a toggle switch hard-wired in. The stock radio had a positive wire to each of the 4 speakers, but only 2 negative wires. The front pair share a negative and the back pair share a negative. So both front grounds from the radio go to a single ground wire and both rear grounds go to another single ground to the speakers. The speakers are all 4 ohm and the radio is rated for 4-8 ohm. Could sharing a ground cause the speakers to be wired parallel and lowering the resistance? I don't think it is a ventilation problem, because there is more space behind the unit than if it was in a vehicle.

Somebody please help me out.

 

[rschap1]

Re: Need Help with New Radio in Boat

If you have a newer deck it is probably "high powered".
There was probably a sticker on the deck saying not to ground the "negative" leads for each speaker.
These should probably not be tied together either.
The old deck may have not had an amplifier section built in at all, but guessing new one does and will need four + and four - wires to the speakers.