Kelvinator Dryer ModelDET400K (electric)
To check the coil, the easiest thing to do is to use a volt-ohmmeter and check the coil's resistance. Low resistance is good - infinite resistance (an "open") is bad. (I have a ***** washer/dryer combo and most of the stuff you'd need to get to is accessible from the back.)
You should be able to see the ceramic block and I guess you're trying to see if it's broken. I think its only purpose is to serve as an insulator, but I don't know for sure. As far as the heating sensor goes, I guess you can use the vol-ohmmeter on it and see if it's stuck open (infinite resistance) by measuring across the terminals.
I hope this helps some! Jim D/Heathsville, VA