old ice maker didn't make ice

After shutting off refrigerator and shutting off water to unit, I removed both freezer food baskets and the door. Loosened screws and removed old icemaker (unpluged wire harness). Took wire harness and front cover from old and plugged into new. Placed back into fridge, plugged in harness, made sure fill tube was properly placed and reconnected door and replaced food baskets. Turned on water and power. Had ice cubes in about one half hour--and I'm getting more ice than I ever did before. THANKS