fusible link testing

I'm not sure if the fusible links are multistrand inside or what but you need to do a voltage drop test on any questionable section of wire.

Measure the voltage from one end of the wire to the other. 0.2 volts "dropped" is about average. Anything more and there might be an issue.

Here's why: Picture a multistrand wire with ALL the strands broken and disconnected, except one single lonely strand. That single strand will register near-zero resistance just like any other wire but the wire will drop tons of voltage because it's forcing all the current through that single tiny little strand. Think of the wire as "using" up a lot of voltage just to force the current through that single strand.

You can see why this is bad, and you can see how it would fool a simple resistance test.