sharp carousel II microwave/convection oven

I just purchased an ’87 Holiday Rambler Alumalite that has a Sharp carousel II microwave/convection oven in it. I did not get an operator’s manual with it. I can’t seem to get the convection part working. The microwave seems to work ok, ( except for popping popcorn ) 🙁 , I know that it should be pretty self explanitory 😳 . Is there any one that can either point me to an operator’s manual or give me some pointers? It would be much appreciated! Thank’s.