OK, the saga continues.
I replaced wiper relay about a year ago but I only have vague recollection of fuse panel, and at the moment it's raining so I can't refresh memory. I think it's a honeycomb affair that flips down and has fuses and relays on one side and a bunch of connectors on the other side. The manual is no help (again!) but I presume there are some jumpers pre-installed on the panel before the fuses, relays and connectors are mounted. If you can check this out and report it would be helpful. It would appear logical that connectors line up with their plug-in device wherever possible, so how many connectors line up with timer? r12?
It maybe easier to cut wires going to connectors and run them to your own little mod box. In this regard it appears the ultimate connection to ground via r12 maybe easily severed and could then serve as your point to inhibit lights. Unfortunately that connection is also the timer's ground (pin 16 on diagram,pin 15 on pin-out) so you would have to remove onboard jumper and run a separate ground for timer.