Sounds like the Z re. m&b [make and break] is the issue.

Aztec z-t.JPG

_{Post edited by Pin-it: Ignore this posting}

I seem to have mis-understood your issue,going back to your first post you are saying that → one of the targets, 'T', both the T and the Z light up in the upper right lane.

If you follow your 'T' relay make and break[yellow wire -yellow orange]were to back feed then the T & Z targets would both light,not the 'Z' m&b as i pointed out in the previous post.
I would check the 'T' relay m&b [probably barely touching]would cause what your getting.

T-Z.JPG

Patience and a continuity tester/Dmm would be the next option if you dont see anything.