First, the Sears repairman diagnosed the switch as broken, and told us that th part, if it were available, would be $150 plus labor. However, he said it was not available, so we'd need to get a new counter top stove all together. Not.
I came to Parts Select, and I found the fan control switch listed here (if you found this story, you've found the right part). In one day, I had the part in my hand...the part that Sears said didn't exist.
First, I turned off the main fuse switch controlling the stove top! Very important! Then I tried to heat up the elements to verify that the electricity was disconnected.
I removed the glass top, then the pan, then removed the side screws that hold the flange in place, the same flange thae holds the knob control area in place. Then I removed the knobs (they just pull right off). Then I removed the knob control area. A small nut holds the fan control switch in place. Remove that, then the switch is loose under the control area. There are 4 wires, but two are connected to each other, so don't panic! Swap them out for your new part, and at this point, very carefully, turn on the main electric again and verify that the switch works. It should.
Turn off the electricity again, then mount the switch up under the control area. There should be a little, bitty tab on the control switch box that fits perfectly into the metal control panel, just to the left of the hole for the stem of the control switch--proof that this switch is meant to be used on this Jenn Air Expressions model CVEX4100/4270/4370 series counter top.
Then reverse the steps to replace all the panels, knobs, pans and elements, and you can cook without smoking up your kitchen, all for thousands less than a brand, new appliance.
Oh, one more thing. The nut around the old switch cannot be used on the new switch. However, you can use a nut from a coaxial cable fitting! It is the same thread count. I used mine from an RCA In Line F Connector 4 pack...part number VH664N.
Other Parts Used: