'73- Crossed 12V circuit wiring?

[TomsEid]

Hi everybody...
I'm a newbie just starting to redo a '73 International 27'. It appears the 12V wiring circuits are crossed or mis-wired somehow. The yellow wire circuit seems to be fine (bedroom alcove & reading light, overhead light), but the pink reads as a closed circuit with my continuity checker, even when I've got everything turned off that's supposed to be on that circuit (other overheads, range fan). But the continuity signal goes off when I turn on one of the yellow circuit lights! Tried to make the pink circuit hot on the new fuse block, but then when I turn off the yellow circuit light, the pink circuit fuse blows.
It would appear that the yellow & pink are crossed somewhere or miswired or mis-grounded or something, but I can't figure out where or how. Anybody have any thoughts, plus let me know.
Thanks,
Tom