My fridge is having some ice build up on the back near the vents. I had a guy come out to look at it, and without even moving the fridge (he only opened the freezer), said it was the defroster fan. Now, I've been waiting for the past 2 weeks to get it fixed, but he says the part is backordered. I went online, and got parts from different sites. The guy said he doesn't mind if I order the part. What exactly do I need to buy? It takes about 3 days to get a hold of this guy and I can't wait to order the part and fix it. Any ideas? Thank you all for your help.