Originally Posted by seattleboatguy
I was wondering about that when you get to a big bus bar. Thank you for mentioning it.
If you connect it to the outboard end of a wire that connects to a buss bar, the signal will appear in all the wires connected to the buss bar.
Go to the buss bar end, disconnect the wire from the buss bar, hook the toner from that wire to ground and you should be able to find the other end of the wire. If the wire is part of a cable or bundled with other wires, there may be some crosstalk and several wires may have the signal. One will be louder and that should be your wire.
Unless there's a junction or splice, the wire you are looking for will be the same color, size and brand at the other end so if you're tracing a red #12 wire, it should be a red #12 wire at the other end.