Question: A friend of mine and I were working on my boat yesterday and installing a new stereo set. I was a bit surprised when he said he thought we needed to change out my entire fuse panel since as far as he could tell it was automotive-grade and not rated for marine use.

Pull the fuses one by one and scrape the prongs with a knife blade. Marine-grade fuses will show bright copper or brass under the tin coating.

Pull the fuses one by one and scrape the prongs with a knife blade. Marine-grade fuses will show bright copper or brass under the tin coating.



I sent along a photo of the panel in question. Help! Do I really need to buy a new panel? I’m the original owner of the boat, and the panel you see came right from the factory.

Answer: OK, you can relax—the panel is quite acceptable for marine use. What may be a bit of a concern, though, are the actual fuses. The ATO-type fuses you have in your panel should be checked to make sure they are marine-grade. Some of the automotive ATO fuses I’ve encountered over the years use an aluminum element and contacts. Aluminum is categorically a bad choice for electrical work on boats, even though we do still see it from time to time.

The way to check this is to remove the fuses one by one and check the prongs protruding from the fuses by scraping them with a pocket knife blade. They may all be silver-grey in color, but if the fuse is marine-grade you’ll be scraping a tin coating down to shiny brass or copper, which should be clear to see. If your blade just peels the surface away and the color remains the same after a few scrapes, get suspicious—those prongs are probably aluminum.

But again, don’t panic. All you need to do is swap out the automotive fuses for some marine-grade fuses. You don’t need a new panel.

 

Written by: Ed Sherman
Ed Sherman is a regular contributor to boats.com, as well as to Professional Boatbuilder and Cruising World, where he previously was electronics editor. He also is the curriculum director for the American Boat and Yacht Council. Previously, Ed was chairman of the Marine Technology Department at the New England Institute of Technology. Ed’s blog posts appear courtesy of his website, EdsBoatTips.