the continuity part worked great . hooked to one end and traced back till i found signal. but using transmitter to trace wire that was broken the tone changed very little no enough to tell wire was broke . in a 10 wire bundle it carried signal 8 feet past break in wire ,. as if the other wires were carrying the signal as they were so close to each other . using the continuity light i could chase the wire color back but had to expose parts to test until there was none then looked for break