Thursday, January 27, 2022


A spot for a spare fuse could brighten your day

By Russ and Tiña De Maris
We had a peculiar problem come up. It was after nightfall and we were preparing to make a foray to the Land of Nod, and the wife had already shuffled off to the bedroom. I was busy brushing my teeth when I got one of those “Honey, something’s wrong here” shout-outs. “The light just went out here in the bedroom.” One more thing to do with my spare time. Happily a spare fuse helped in the end.

At day’s end, my thinking mechanism is never at its best. By the time I could ponder the “why did that happens” and stumble my way to the bedroom, the light had mysteriously turned itself back on. A couple of days later, the complaint resurfaced – this time, the light wouldn’t turn on. I suspected perhaps a “bum bulb” and was about to start into the fixture, but I needed more light on the subject. Reaching up to the ceiling light switch, I was mentally illuminated when that light wouldn’t illuminate. Obviously more here than a bad bulb.

I racked my brain to recall if I’d recently drilled any holes or driven in any screws that might be responsible for setting off a loss of power to the lighting circuit down in the bedroom, but drew a blank. So off to the fuse box, where I nearly had to stand on my head to read the circuit tags. Do I have a spare fuse? I started to pull the fuse serving the bedroom circuit – only to have the lights pop back on. “Ah, just a loose fuse,” I chortled.

Yeah, and I’m a loose nut

Because, sure enough, within days, the bedroom blackout returned. This time I pulled the fuse out for a closer inspection. The fuse is one of those contemporary plastic-bladed style fuses, and a quick look through the window on the fuse didn’t show anything suspicious. But a closer inspection of the blades revealed blackened pitting on the blades – the telltale sign of electrical arcing, brought out by a not-so-tight connection.

Arrow shows “spare” fuse positions. R&T De Maris photo.

In a “what’s to do now,” situation, I thought about disconnecting the battery power to the fuse box and taking after the fuse clips in the box with emery cloth. I’ve dealt a “temporary fix” to such problems in a shore-power breaker box, but always sweat bullets about possible outcomes of such a stunt. I pondered drilling out the rivets that held the fuse clips and trying to get a replacement clip. But then my own light came on – there were a couple of spare fuse clips in the box.

So I simply removed the hot wire from the “downstream” side of the offending fuse clip and hooked it up to one of the “open” fuse clips. With a fresh, unpitted fuse, I soon had the lighting circuit lit up again, with no qualms about safety.


RV Electricity – Just Ask Mike (J.A.M.): How to meter a fuse

RV Electricity – Don’t fix a blown fuse like this!



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4 months ago

Very simple fix for a simple problem, good on ya!

A simple tool that is only needed once is to take an old fuse, break it in half and use a half piece to ‘clean’ and check the tightness of each blade connection.
Remove a fuse and insert the new “tool” into each blade connection and insert/remove it a few times. You will be cleaning the connection and also get a feel on how tight it is. Too loose? Needle nose pliers can carefully squeeze both tabs on the female part, too much squeeze and use the tool to separate it again. Also a quick cleaning of the fuse will finish the job. But use a pencil eraser on the fuse tabs, emery is too harsh for the metal.
Anytime I am doing “maintenance” on my fuse panel, I will remove and reinsert a fuse just for a quick check/clean.

Randy R
4 months ago

So what does mike think? Personally, I think arcing is an indication of a problem or something! There is not enough weight to cause the fuse to become loose and the spring metal connection should not become looser.

4 months ago

And what does “Ask Mike” think about this, yay, nay? In a pinch, why not.