Rear defogger not working

[Be_Jammin]

Hi, I'm having a bit of trouble with my rear defogger: I switched the tailgate on my hatchback for one with a window wiper, initially I though it was okay, as the window mounted light was working, but a couple days later I attempted to use my defogger and discovered otherwise.
To troubleshoot I did the following:
1) I checked the fuse; it's fine.
2) Verify the defogger was receiving electricity; around 12 volts across positive window tab to ground window tab.
3) Check the Bus for electricity; around 12 volts from one side to the other.
4) Check each parallel line for conductivity; most show around 12 volts, however a few do not.

This is was confuses me, since the strips are wired in parallel, shouldn't the defogger continue to work on the good lines? There is zero heat generated from any of the lines.