Hi, I 'm new to this forum and I think it's awesome! There's alot of knowledge here so I'm hoping someone can answer this for me. I'm trying to replace the stock 1987 Maxxima cassette stereo with a new stereo (wiring diagram came with the new stereo), but I have no idea which stock wires (from the boat wiring harness) are for the front left/right and rear left/right speakers. I assume red is for power and black is for ground. If anyone knows the stock wiring harness color schema or knows where I can find this info it would be greatly appreciated! The boat didn't come with an owner's manual. I hope I provided enough info from the subject line and this post. Thank you!

you will need to get a mini 9v battery and do the pop test on the speaker's..Watch the speakers as doing so,if your on the + side of the battery and the speaker move's out then that wire goes to the + side of the radio output,if the speaker move's in then the opposite would be the + wire..

Are your speaker wires color coded ? If so, pull each speaker and note the color of each + and - and wire to your new harness. You'll need a meter to check your 12v source. I doubt they had any thing in the manual about stereo wiring. Read and follow your installation instructions, they may require two hot wires.. Good luck