Ice keeps forming in my top mount freezer and water keeps dripping into my fridge. I let it defrost for 24 hours and dried it all up. I stuck a wire down the freezer drain. Poured water into the drain and it passed through. No clog. Within 20 minutes of plugging it back in the water started dripping again. It happens nonstop all year round. The water supply line isn't even hooked up. What could be the problem?