Lost continuity between battery and starter solenoid

Was at a mall (Strip type) the other day (well months ago) and some folks where working on a Pick up no start.. Grabbed the volt meter and started poking around One end of the main battery cable had 12 volts the other end zero. bad cable or bad lug don't know which . Split before they fixed it.

My suggestion is a test light over a voltmeter (Easier to read) start at the battery or at the generator and work toward the other end. Problem exists between dark and light.