How to determine unknown fuse size!

[plt3145]

Haven't been on here for a while. Got a new to me 1990 161 Fishing Machine Sea Nymph, 40 Hp Johnson. I am starting to undue rat hair of rewiring by previous owner... but want to be able to fish for season. I will not be replacing original wiring until fall so I am cleaning up the electrical connections that I can see. MAIN QUESTION: P.O. has run main wire from battery to buss bar and fuse box. He had soldered in an in-line fuse close to the battery. Great! I can deal with that, but I want to change the in-line fuse to a replaceable type fuse. PROBLEM: Can't see what size fuse it is. How do I determine what size fuse is being used now? Surface of fuse is unreadable and corroded. Can ya help me? #-o

 

[CedarRiverScooter]

I would fuse it for the actual wire size you have. Measure the diameter of the actual wire, not including insulation.

You can then figure out wire size & fuse size from internet search.

 

[skipper123]

Install a smaller fuse like 3 amp and start turning on loads as you would use them. Use a inline fuse holder with #10 wire if possible or one that you know is large enough wire to cover all that may be on at one time. If the smaller fuse blows up one size until it holds all that you plan to run at one time. Whamo you now have the correct fuse size. Just large enough to hold the complete load demanded of it. You may also need to install a fuse on each item you plan to run, all loads require a different fuse size for each appliance.

 

[plt3145]

Cedar and Skipper, thanks to you both! Can I say duh! Thanks again...TIGHT LINES! WHAMO!