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Replacement parts for TEDS840JQ models | AppliancePartsPros.com
See the attachment for the tech sheet.
The last digit on the model number was missing so I used a JQ1.
You said "doesn't seem to be grounded", I am going to assume that you checked the heater resistance and for grounding with a meter and everything read normal.
My fist guess would be that the operating thermostat's contacts are welded together. You could check this by heating up the face of the thermostat to see if the contacts will open. I use my soldering gun but you could also do it on a stove element. Just be careful that you do not burn yourself. If they do not open then you know for sure that it needs replacing.
Also note which wires go where when removing the thermostat as it is a 4 wire (2 for the contacts and 2 for the internal heater).
If it does open it does not eliminate tthe thermostat as it may open at too high of a temperature.