Surface element control problem

Question

Older jenn-air (Model 88370). Front control causes both front & rear elements to heat up (that's the problem). Rear control only causes the rear element to heat up. So it doesn't seem to be a short between the element wires. This unit uses what the parts people call an ''infinite switch control'' for the controls. The controls have what looks like L1 & L2 terminals, both in & out, but there is a fifth terminal of unknown purpose as well.Before I just go & replace both controls, I would like to find a schematic, as the one that was pasted inside the compartment is destroyed.