Is the Speed Heat switch currently installed in your range is larger the other ones and has screws to hold the wires on it's terminals rather than connectors? If it is, it hasn't been converted yet and there should be two hot wires (marked "L1"-"L2"-for 240V operation) and a neutral (marked "O1" for 118V operation) connected to it, the other terminals are "P" for the pilot light and "B" and "R" for the wires that go to the burner.
With the range disconnected and with the burner drawer pulled to show at least the two front burners and locked in half-opened or fully-opened position, you can test the wires that go from the switch to the burner (those on the terminals marked "B" and "R"-see picture below) to be sure there's continuity in that part of the circuit. You should read something around 10-15 ohms if the burner is the original 118V and there should be no continuity with the drawer closed. If you read something like 35-45 ohms (I just checked 236V a 6" burner and it's 42 ohms), the Speed Heat burner was already replaced with a regular 236V burner (which is unlikely if the switch is the original type!). If there's no continuity, either the wires, the drawer safety switch or the burner are bad... Flair ranges have safety switches in their drawers so the front burners can't be turned on unless the drawer is at least half-opened and the rear ones can't be turned on unless the drawer is fully opened.
It's possible to replace it with a RobertShaw switch but some square-shaped models turn in the wrong direction (meaning the burner will be on High when the control is set on Low and on Low when set on High...). The numbers you provided show a square type switch that is supposed to work as a replacement for Frigidaire ranges so maybe it's correct...
I think the original-style replacement switches are also now made by Eaton/Robertshaw rather than King-Seeley-Thermos or Proctor as the original ones. These are rectangular and look similar to the original regular infinite switches (some are white instead of black). The original part number was 7521242 for the regular 236V 6" burner swith and it's the equivalent of the 6004-AF7 according to the chart in the link below.
But you'll also need to get a 240V burner to replace your 118V burner. If you want, I can trade you the 118V burner for a 236V.
The old switch does use 240V for the initial "flashing" time to get the burner hot and then cycles on 118 volts.
Maybe it would work with the 118V burner if you connect the neutral wire from the Speed Heat switch instead of one of the hot wires but I haven't tried it. I'm guessing the switch won't cycle correctly... You don't want to have 236V constantly going to the Speed Heat burner as it will be too hot and you'll burn it (or the contacts in the switch) quickly! Connected to 236V, these burners use 5000 watts and neither they or the switches are designed to work constantly under such a load!
[this post was last edited: 1/5/2014-00:39]
