Fan not rotatating - Ovens

armature clean and check capacitor

A lot of ovens have a convection option, and the fan will only work in this position. Otherwise, just rotate your pan halfway through, like we always did.

Remove the cover at the rear of the oven compartment, then holding the fan blade with one hand, undo the nut holding the fan on, it is a left hand thread, so turn the nut clockwise as though you were tightening it.
To remove the motor itself you will have to undo 3 screws securing the fan motor from inside the oven compartment, then remove the outer rear cover of oven to remove the motor.

The fan motor and axis is full of burned oil and fat and this can make it run harder and heavy.

Also the Fan blades from heat can be deforms and heats the frame while they rotate.

So the first solution is to remove the complete fan and motor clean the axis and use lubricated oil like UD40 and check the fan blade if they are straight. If the fan and motor look very bad then replace it with a new one.

Does the rack raise? Are you hearing a buzzing every second? You could have a bad rotation motor, or the drive chain could have just fallen off. Both of these repairs aren't terribly difficult but are extremely annoying. It might be a best use of your time and resources to call an authorized service provider and have them repair the issue.
If you're feeling ambitious the first thing you want to do is verify that your rotation motor is still functioning and that the gearbox is not stripped out. Make sure the supply power to the oven is off, climb up on top of the oven and remove the covers over the lift and rotation assembly if they are not already removed. You should see a black cylindrical motor with a plastic fan blade on the top, this is your rotation motor. Spin the fan blade with your finger while looking at the motor shaft, it should be rotating, if it is not you need a new motor. To change your rotation motor you will need a 5/16" ratcheting box wrench and it can be a nightmare the first time you change one. Unwire the motor, pay attention to which wires you disconnected. Remove the four screws underneath the motor and slide the motor straight up through the hole. Change the chain sprocket over to your new motor and reverse the steps.

If your motor IS rotating when you spin the fan then your chain may have slipped off. Loosen the four screws holding the rotation motor in place so you can slide it back and forth. Lift up on the shaft and place a screw driver in between the metal disc above the big sprocket to keep the weight off of the sprocket. Put the chain on the small sprocket first and then slowly work the chain onto the large sprocket. Once the chain is on lower the shaft back down and tighten the motor back up. Hopefully your rack should start rotating again, if it doesn't the gears in the gearbox could still be stripped causing it to slip, in which case you should call an authorized service provider to service the oven, or see above.

no/low cooling fan rotation (No RPM) single cavity or upper oven - check connection at cooling fan if ok, replace blower - DO NOT REPLACE CONTROL

It is most likeky that the fan bearing is worn and thus causing the rattling sound. You will probably need to replace the fan. Check first that there is no obstacle in the way of the fan rotating.

Replacement of the fan will require the back of the oven to be removed giving access to the fan unit, which will need to have the wires disconnected and the fan assembly unbolted. Fitting is the reverse.

Always remember to switch off the power before working on electrical equipment.

sounds like the heater element that sits in front off the fan has broke.you can replace them.

Mine had this in a Sears Kenmore Elite, the guy changed the fan relay.