OK - this morning I rechecked the insulated track - no problems there. I disconnected wires going from gates to the relay and power. I tested them using MikeCT's illustration by touching the hot and ground to the rails and then touching white to blue wire and yellow to blue wire - gates worked with no problem. I am now thinking it may be a bad relay - although it was working fine on my old layout. Oh well, to my LHS to buy a new one -
Paul