Thanks everyone for your help I added a connection and it works fine.
i’m disappointed, though, in the product. Belatedly, I’m beginning to think Ross switches might have been the better bet. I have 17 of these Atlas switches, 4-5 being older and defective. (Typically one side of the switch works but the other doesn’t -really obvious ). The thought that shorting would cause those thin wires to break is disconcerting- having to rip up the track, ballast etc. after the fact is not a prospect I relish.
Perhaps i need to take preventive measures before I go much further.
Thanks again