Bringing this thread back from the dead for awareness with this issue.
The bugtracker issues are already approaching issue number 5000.
Yet this problem with fused wiring, as well as the target dummies not doing their taunting function as they should, was reported even before issue 1000, almost a whole year ago:
https://report.nostalrius.org/plugins/tracker/?aid=845I have just added a lengthy post with sources and feedback detailing that it should work. The drop rate of fused wiring from dummies, compact harvesters, alarm-o-bots isn't defined rigourousy anywhere, likely due to lack of interest, but the approximative comments tend to gravitate to something around 15%.
If you are an engineer, you know the prices fused wiring sees daily in the Auction House, and as it stands, only farming Gnomeregan or specifically hunting a rare mechanical mob in Searing Gorge or the shredder of STV provides this item.