Mold in your ice maker is not something that should happen if it's being used per installation instructions. If you're not certain if your ice maker is installed correctly, consult your owner's manual. If mold is present, you can add 3 cups of vinegar to the water line with a funnel and turn on the ice maker so that the vinegar runs through the dispenser. Use a cup to catch the vinegar and use a toothbrush and rag to scrub the dispenser clean of any residue.