Hello my name isXXXXX will assist you today
I am looking at the parts breakdown, but it is not showing all the wiring.
If the top oven is not working but the lower oven is then most likely what has happened is a thermal fuse has gone bad, or a wire has burnt into
One of the main problems is when looking at the parts breakdown, the majority of the parts are no longer available.
If you are going to have a person fix this for you, I would go with a local repair company that you trust, I am from St. Louis, and it is hard to recommend someone when I'm not living there. You can also log on www.whirlpool.com and schedule through them and they will send out a authorized repair person, to look at this for you.