Mark,
if it is the older N scale loco with white exposed gears in the trucks then the pickup strips sit between the back of the wheels and the gear case, The semi-circular loops are up on the top, pointing outward. When the truck is mounted in the chassis, that puts pressure on the loops which then press the flat pieces of the contact strip against the backs of the wheels.
The model should have included an assembly diagram and parts breakdown in its box.