the selector lock trip relay needs to be tripped. It should trip when you shoot the 4th ball.
if that's ok, I usually just grab the spinning search wipers with my thumb and move them around to a point that at least three adjacent search relays are powered, at which time the search index unit should power and hold the wipers.
the goal of moving the search wipers yourself is to see what the search relays are doing.
you can also carefully slide a piece of paper between the 120V switch contacts on the tilt trip relay switch L2 with the plastic coated wires on the blades. That will turn off the motors and you can spin the search wipers to anyplace you want.
you can look at the chart on manual page 25 and see where the wipers need to be to detect any win you set up.