OK thanks again...that's a great help.
I have verified that the new DB15 Y Cable that I received from Elecraft is a dud. There is no DC continuity between the female ends and the male end on all PINS 4-12 inclusive and also PIN15 . Only on PINs 1,2,3,13,14 have DC continuity between all the connectors. I have checked it several times.
The E850463 cable I have has the correct connections on the PINs listed in the KAT500 manual. I now know why the K3 remote will not turn on and why the KAT500 does not track properly.