Finding the Right Fuse Dimensions

liveincolor · #1 (**permalink**) 06-15-2011

I have a Hurley 20' (1970). The other day I connected a fully charged battery in an attempt to use my depth gauge and lights, but nothing worked. I discovered nothing worked because there were no fuses installed (the glass tube kind) in the fuse box.

My question is this:
How do I find the fuse with the correct dimensions (diameter and length) for my specific setup? I know that each fuse should be 15A, but there is a wide variety of sizes varying in diameter and length that come in 15A. I discovered one size that fits snug (diameter wise) inside the screw cap that contains the fuse, however, when I screw the fuse into the receptacle it is just a hair to long and doesn't allow me to screw the cap all the way in so that it is flush with the fuse box.

tommays · #2 (**permalink**) 06-15-2011

I will guess its and AG fuse which has common lenths of 7/8" / 1" / 1-1/4"

liveincolor · #3 (**permalink**) 06-15-2011

Thanks for your response. For my own experience and learning, what makes you guess that I need an AG fuse? What are the characteristics of an AG fuse that differentiate it from other glass fuses?

mdbee · #4 (**permalink**) 06-15-2011

Why not take the fuse that's too long to the auto parts shop and find one a bit shorter? Note the lengths the previous poster gave. What is the wrong fuse's length?

Quote:

Originally Posted by liveincolor

Thanks for your response. For my own experience and learning, what makes you guess that I need an AG fuse? What are the characteristics of an AG fuse that differentiate it from other glass fuses?

liveincolor · #5 (**permalink**) 06-15-2011

That's what I intend to do. I'm not positive of the length of the fuse as I do not have them on me now, but I will know later today when I stop off at the boat. I guess my real question/concern is, can I potentially damage or break anything by using the wrong fuse (as far as dimensions go, amperage is correct) when I connect the battery to test? The fuse I have in there now is so close to the right size, but I'm a little concerned with how snug it fits...I'm pretty confident I'm not forcing the fuse into place, but since I have no experience with these glass fuses I don't want to assume anything. I can't imagine it should be a looser fit, but like I said...I have no idea.

tommays · #6 (**permalink**) 06-15-2011

AG stands for Auto Glass and while there are endless possible fuses IF the panel was American in origin it would be the most common thing used

If the fuse fits tight and makes good connection in its socket you do need to look at the wire size used as 15 amp WOULD PROTECT 14 GAUGE WIRE and you never know what some crazy PO installed as i have to assume there is some kind of issues IF there are no fuses in the panel

Stu Jackson · #7 (**permalink**) 06-16-2011

These fuse holders are spring loaded. They do, therefore, require some "effort" to push them in and hold them in place when you then turn the holder.

hellosailor · #8 (**permalink**) 06-16-2011

http://www.littelfuse.com/data/en/Da...ermarket-8.pdf

A nice one-page description and explanation from one of the better makers. Note that the LENGTH also depends on the AM RATING in a roper installation.

There are other variations like "fast blow" "slow blow" "instrumentation" but for boat lights and similar uses, plain AG is fine and all the others will arguably work just as well, as long as you get the rating right.

Any auto parts store should sell an "assorted" box, half useless, the others more or less right, maybe $5 for ten fuses. Put a little silicone grease over the ends of the fuse to prevent them from corroding and bonding to their contacts. Sparingly.