Turn off the oven circuit breaker.
Open the lower oven door, remove the screw on each side trim, pull the bottom of the trim toward yourself and slide it down to release it from the control panel tab.
Remove the screw on the bottom of each side of the control panel. Pull the bottom of the control panel toward yourself and up to release it from the tabs.
Locate two identical relays on the control board with two wires plugged into each of the relays - 2 red wires into one relay (we will cal it relay#1) and one red and one red with white strip into another (relay#2).
Remove the red wire from the relay#2 and both red wires from the relay#1. Check for continuity between the first red wire (relay#2) and each of the red wires from the relay#1. Mark the red wire (relay#1) which has the closed circuit with the red wire (relay#2).
Plug this wire and the red wire from the relay#2 back in place, living the second red wire from the relay#1 out (insulate it).
Turn the oven circuit breaker on. Turn the Bake on the upper oven on and check for 120VAC between the terminal on the relay#1 where the red wire was connected and ground.
Post the results.