Look into an rf injection tool if you don't want to isolate an open circuit by measuring voltage. Just curious but is there a reason you can't isolate the problem with a voltmeter? Do you already know which wire is open and are trying to repair rather than replace?
RF or ac signal injection is similar to what an electrician or cable tech would use to find an open in a buried cable (bad, painful, and expensive lessons !!!).
As Jack said, inductive sensing won't work for an open wire.
I've never used one, so can't comment on effectiveness nor ease, but here's an example of a cheap version:
https://a.co/d/5cZslmt
I'm sure there are higher quality tools if you need to go there, but I kind of expect a voltmeter would be a simpler approach.
Mike