04 PT 175-wiring questions, missing negative?

[dmc575]

Recarpeting my boat. Planning to just keep wiring as is, but I was looking at it and im confused. I see no negative connected to the fuse box! All switches and accessories work. Also....the starting battery has 2 small guage negatives and 1 small gauge positive connected. I was confused why there was 2 negatives...and even more confused when I saw NO negatives connected to the fuse box/panel (not sure the proper term) up at the console.


Here you see the whole fuse panel.


Here you can see where the positive is connected to the top of it.


Here is the bottom where I'd figure there would be the negative, since that is the negatives that are connected there. but there is no post. I tried rooting around to see if it ripped out...and nope. All looks normal beside that missing negative.


I ordered a new fuse box and was just gonna transfer it all over....now im just gonna keep it completely as is and just switch out the covers cuz I dont wanna mess anything up (first boat and im far from an electrician! lol). but thats what got me looking for the negative connection, and I just didnt see it.

[Lowerider58]

If you can follow the three black wires I expect one of them goes to a ground buss and then back to the negative post on the battery.
As far as the red wire on the battery negative you’d have to try to follow it to see where it goes or disconnect it and see what quits working. It may be a wire someone added aftermarket.

[R2Tracker]

I suspect it to be the black wire with the yellow insulator around the terminal, as that one appears to be a thicker gauge wire in your picture. Is that the same gauge as the red wire from battery to fuse panel?

[dmc575]

I suspect it to be the black wire with the yellow insulator around the terminal, as that one appears to be a thicker gauge wire in your picture. Is that the same gauge as the red wire from battery to fuse panel?

I do believe it is a little thicker! Nice catch!!! ill double check tomorrow

IF it is the negative....and if I disconnect it then that would mean the panel wouldnt work, right? So thats kinda a way to test if it is the negative from battery, right?

Thanks!!!

[Bill Reynolds]

Any of the black wires will be ground. This is a ground connection bus which allows you to connect the ground side of accessories like graphs etc. ( the positive lead of the accessory would be connected to an available fused connection point on the board). I agree with others that the larger of the two black wires goes to the battery and I see two other connected black wires that are probably accessories.
If you want to test which of the black wires goes to the battery, disconnect the wire from the block, hook the red lead of a voltage tester to the red wire on the block and the black lead to disconnected black wire. If you read 12 volts, this verifies that this is the correct wire.
The following pics provide the color codes for accessory wiring on your boat. I had to break the screen capture into 2 pics so some of the info is duplicated.