blade fusesI

I discovered something. There are two open holes on top of the fuse where the amperage is printed. These holes are there for access with a multimeter and check for continuity. An easy way to check the fuse.

seattle##gs said:

I discovered something. There are two open holes on top of the fuse where the amperage is printed. These holes are there for access with a multimeter and check for continuity. An easy way to check the fuse.

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Yup! Some fuse kits come with a small plastic gripper thingie to help pull them out of a fuse case when they are all crammed in tooth to jowl. Sometimes these "tweezer" tools also have a built in checker, a battery turns on a little LED when the two contacts are in place with the fuse contacts you just discovered. Helps ID a blown fuse while still in the fuse box.

Finally, there are fuse holders that have an led next to each fuse location, which light up if that fuse is blown. I had a single fuse holder with led on my Commando a few years back. No idea how it powers the led with blown fuse, some kind of hidden, embedded battery?
Anyway i did not refit it when a new wiring harness was installed.

Tornado said:

Finally, there are fuse holders that have an led next to each fuse location, which light up if that fuse is blown. I had a single fuse holder with led on my Commando a few years back. No idea how it powers the led with blown fuse, some kind of hidden, embedded battery?
Anyway i did not refit it when a new wiring harness was installed.

Click to expand...

They allow current to pass though the diode (LED) when the main fused section has blown. Neat feature, but one problem is they allow a small amount of current to pass through, making it hard to trace a short or potential problem with a volt meter. Will give a false reading, something to be aware of when trouble shooting.

Tornado said:

Finally, there are fuse holders that have an led next to each fuse location, which light up if that fuse is blown. I had a single fuse holder with led on my Commando a few years back. No idea how it powers the led with blown fuse, some kind of hidden, embedded battery?

Click to expand...

The LED/resistor are across the fuse. When the fuse is good, the LED/resistor "see" no voltage as the fuse is a short across them. When the fuse blows, the short is gone so the LED/resistor "see' the voltage and light up. Long before LEDs, fuse holders in expensive systems like mainframe computers had the same concept but with other sorts of lights depending on the voltages involved.