Good Enening everyone, new member and first time poster

My question has probably been thrown around a lot. I have no power being transmitted to the rear wheels. I've done a bunch of reading that suggests that the oil pump on the rear differential might be bad. But I've also read that when it does it takes a fuse with it. None of my fuses are bad. I don't want to recon by fire here and just start throwing money at it. Any trouble shooting tips before I. Real the bank? Thanks a bunch for the help.

Mike