Islander 268 Fuse box and trim tabs

In your manual is a very good listing of color coding (for the wires) and the fuse amperage that protects each circuit. You can use that to figure out the circuits. You can also pull fuses one at a time and see what circuit no longer works.

Of course, at 20 years old and who knows how many owners, you will most likely find that some things have changed. Which means what you currently have could very well be different from the manual and also from other owners. Looking at that picture, it doesn't appear that everything is factory. You'll just need to figure things out - take notes/write things down.

A little bit of bleach/water and then a soft brush a few minutes later will clean things up. Disconnect the neg lead on your batteries, first, just to be safe. Then remove every fuse and connector, let them dry, and reconnect with a small amount of dielectric.

ElMar, I have the same boat. 1999 Islander 268. Mostly stock, except for electronics. Let me know if you have any questions. Message me or PM me...

20 amp in number 6 for me.

The ZEP mold spray that you can get at Home Depot works well and it is a lot less expensive than the 'marine' products. Any bleach based cleaner like it should be rinsed off and you have to protect your self (and clothes) from it.
Power has to be disconnected as mentioned before cleaning and rinsing.
Your fuse block looks fairly corroded. You should mark all cables and then remove it, clean all screw terminals and spade terminals. A brass wire brush and some fine emery or wet sand paper will do. Remove the fuses (mark where they go) and clean the fuse lugs as well as the sockets. The inside of the spade sockets are tough to clean. A small round metal brush is helpful or a small strip of emery paper wrapped on a narrow thin piece of sheet metal (like aluminum flashing) can do the job If the terminals are really shot, it makes sense to replace the whole block. After all is reinstalled, coat the assembly with a light spray of something like Boeshield T9.

One observation about your wiring.There are two rather large wires connected to circuits 7 and 9. The fuses are not large at 10 and 15 amps but I wonder what those wires are connected to. Perhaps that was the wire that a previous owner had on hand for adding something.

Sorry, I didn't mention the issue with the tabs. There are a reasonable number of parts and connections in the tab circuit and you may need to test all of them working back from the pump or working forward from the fuse block assuming you are sure what circuit it is. Before anything, using a test light and a known good ground, test that there is voltage(battery on of course) at every spade wire terminal. They should all have juice. If they all do, then do the testing from the pump back. If any don't have power, fix that first. If would be a bad connection, fuse socket or fuse.
Remember that grounds are as important as the hot feeds so you could have a perfectly fine fuse block and fuses but a bad ground at the pump.

You might need to test the pump itself, the relay and the trim switch.Don't forget to check the connections at the trim switch too.

Good luck.

I replaced the fuse block in my GW 223 and I used this. For $30-$35 it was well worth it. Blue Seas 5025.