I turned my water on in the tub, let it warm up then turned the shower on and got this loud horrific noise. I immediately turned the shower off and the water was running just fine from the tub faucet. I turned the shower back on, same noise, but water was not coming through the shower head. I took the shower head off, checked it, then turned the water on to see if it would flow from the shower pipe. It didn't, but still comes through the tub faucet. I just bought this house 3 months ago, so have no idea what brand anything is. Thank goodness I have a second bathroom here because I have to have my shower, I am not a bath person. Can anyone help me?

Show us a picture of the valves. For what you have described your diverter must be on the wall.