This oven does not work on the convection setting. The fan doesn't come on, ever

Here are your parts
Parts for Frigidaire PLCF489CCF Range - AppliancePartsPros.com

Here is the wiring diagram
http://manuals.frigidaire.com/p...assomption/318045330.pdf

If both the convection fan and the convection element do not come on then odds are that it is the control board.

If the convection element works but the fan does not then it still could be the control board. But may also be a bad fan or a bad Auto Door Switch(Normally Open side not closing when the door is closed).

Unfortunately I do not know where this switch is. They just show it at the end of the listing in the Body Parts section but do not show it in the parts breakdown.
I am doing a bit of guessing that this is the switch as they do show the door switch as a separate item (12 and 12A).
To confuse things just a little more they show 12A as a Door Switch ( 2 prong - has common and normally closed) but also show a item 12 as a Switch [3 prong -has a common and a normally open and normally closed (a bit of a guess on my part)]. So they may have combined the two switches.

Perhaps rickgburton has some input on this.
Or someone who has had this problem on this unit.