Hello Shartrick,
The problem is the switch its self it is letting the power run thru it and not turning it off. You will have to take the back off of the range and locate which one goes to it.
1. Remove the cord!
2. Take the back off and locate the switch, Pay attention to the lines as they will have to go back to the same ones L1 to L1 of the new switch and L2 to L2 crossing these will burn up the other switches.
3. Remove the old switch pull wires first. Unscrew the two screws on the front that are holding the switch.
4. Screw the new switch in place and replace the wires
5. Replace the back of the range
6. Plug in and try the unit.
The switches can be purchased at
www.easyapplianceparts.com
For the 8 inch burner switch #
EAP336989 Cost $39.65
For the 6 inch burner switch #
EAP336885 Cost $40.18
The full web page that you need is
http://www.easyapplianceparts.com/MultiModels.aspx?ModelNum=gr399lxhs&searchTerm=img_D4IXLDKW&RefineSearch=0&imgMfg=Whirlpool
Thank you for choosing FixYa