Quoted from DakotaMike:I know that you need to pull them to be 100 percent sure, but never fully understood why. Since the fuse tested good, and didn't visually look blown to me
Because it's measuring the resistance from one end of the fuse to the other. When it's in the circuit and the fuse is blown (open) it's measuring the resistance of the circuit now. Depending on the circuit, there could be little to no resistance making it seem like the fuse is good.
If you have a fuse that's blown due to an overcurrent condition you have a 70% chance of visually seeing that the fuse is blown. Sometimes you can't really see a visual indication of a blown fuse. Other times fuses just go bad from vibration and they look good. I'm guessing this might be your situation.
Middletown, OH
