Checking fuses

[russel1972]

Bought a PL 55X that does not start when the switch is in the on position. Have been searching how to get a proper reading. Some sites say it should test 0 or very close and other sites say it should be closer to 5.

I have 0.3 amp glass fuses. Using a cheap multimeter, I set it to the lowest ohm setting wich is 200. Just with the meter on it reads 1. If I touch the prongs together, I get a reading of between 0.2 and 0.5. When I test the fuses with the prongs, both fuses read about 5.0.

Is it possible that both fuses are partly good? With the fuses in, the light on the strobe does come on.

Any help would be appreciated. I can go and get 2 fuses but is it worth it?

As part of my testing, I took a fuse out of a CD player that I was going to recycle. That fuse reads 0.4. The CD player did work before but I went from a 5 disk to a single.

Thanks Al

 

[RVT1K]

Making very low resistance measurements can be a little challenging with "cheap" equipment. Most fuses are simply a piece of wire and should measure very low resistance.

The readings you are getting are probably showing a little corrosion on the metal caps of the fuses which is creating a some resistance. It is also likely the meter isn't accurate over the entire range. Plus the lowest range being 200 ohms shows it just isn't made for very low resistance measurements. If you push the probes more firmly into the fuses does the reading change?

If the fuses were blown, you would see very high resistance, in the megohms range.

Fuses are cheap, replace them for peace of mind but I don't think you need to.

 

[Capitol C]

Another thing to do is to short the probes (press the probes of the meter together) and write down the reading, it is almost never zero. Whatever reading you get when you short the probes should be subtracted from the reading you get when you measure the fuses.

 

[russel1972]

Thank you. I will the fuses and check for other issues,