Bob, Here are my connections from transformer to SC-2 to coral and OTC lockon:
preface, I am powering my accessories from a separate accessory transformer which is properly phased with the track power transformer and TMCC command base.
hot from the accessory transformer to the center post of the SC-2
hot from left post of SC-2 to OTC terminal 1 (for momentary activation of cattle car by pressing Aux1 on the Cab1)
hot from right post of SC-2 to coral (for constant activation of coral by pressing Aux2 on the Cab1)
ground from the accessory transformer to the ground terminal on coral
with the above connections in place, the coral does activate (by pressing Aux2) however the cattle car does not activate (when pressing Aux1).
I also tested with a barrel car (known to be good) and got the same results.
in the process of trial and error I connected the OTC lockon terminal 2 to the ground terminal on the coral. Now both the cattle car and coral activate by pressing Aux1and Aux 2 respectively. Solved, I thought! However, I then noticed that when power to the track is off, activating the cattle car (pressing Aux1 on the Cab1) causes the lighted track power lockon to illuminate (indicating that power from the accessory transformer through the OTC and cattle car somehow is entering the track). I closely examined the OTC, it looks fine. and so I then attached the accessory transformer ground to the track power common ground which results in the track power transformer breaker going off.
So that's where I am at. any advice is greatly appreciated. I will not be the least bit ashamed if called out for crossing a hot with a ground somewhere in the above. Thanks!
