...the 402K kit, only works if there is a cable box connected and powered up for the line being tested. As I recall, the 402K indicated the active line from the DC voltage of the cable box output.
That's completely wrong. The 402K is simply a toner and probe. The CATV version toner has a cable and "F" connector. Like many toners it can also be used as a continuity and voltage tester. It has LEDs that will indicate when it is connected to a short, DC voltage or line voltage. No way can it tell you if there is a signal on the cable.
By the way, a cable box does not have any kind of voltage on it's output (or input for that matter). It's probably a dead short to DC as are most splitters. That's probably what your 402 toner is showing- a short. If the toner is connected into a splitter that presents a short it is unlikely that you will be able to pick up it's tone with the probe on any cable coming off of it. It's the same situation as trying to tone any shorted cable.
Trumpy, the original question was only how to identify which end of a cut cable is the feed. You are right, there is lots more that comes into play and if that was understood they wouldn't be cutting into a cable to install a splitter to begin with.
-Hal
