Oven is a 10+ yo Whirlpool that has recently re-worked control circuit board (E6 F2 error code) and replaced control panel (F2 E1 error code).

Best as I can tell from the parts diagrams there are two blowers with one each for the upper and lower ovens, but I can only see one long squirrel cage type blower at the back of the upper oven behind the control panel.

The upper oven will heat up and seems to operate normally with the exception of no cooling blower fan of any kind. I can feel/hear relay switches making contact but do not know what these relays are doing specifically.

The lower oven will heat up and - here's the weird part - the cooling fan on top of the upper oven comes on.

I don't know if the blower that I can observe is for both ovens and will come on with either oven start or if the upper and lower blower wiring somehow got switched. I don't even know for sure if there are actually two blower fans or if the one blower I can see behind the control panel is the only blower fan this oven has.

Whirlpool model RBD245PDB8.

Any thoughts on how to proceed? Thanks in advance