|The tester cannot test the wiring unless both ends of the wire, or at least the circuit are connected to the tester. It has to be a loop. |
Cable from wall, end of wire at switch, unplugged from switch and plugged into the removable tester plug.
If you just plugged you cable into the tester, it won't test, there has to be a complete loop back to the tester.
We were the unwilling, led by the unqualified, to do the unnecessary, for the ungrateful.
VietNam War Poster