Well, of course, now that it is nut hugging cold, I plugged the truck in and it tripped the GFI receptacle. Thinking there couldn't possibly be anything wrong with my truck (sarcasm inserted), I changed out the GFI. NOPE. Do you suspect I have a ground issue, the grid heater is gone, or the grid heater solenoid? Any help would be greatly appreciated by my cold natured wife

 

I usually suspect a bad block heater cord first.

Also meter out the element on its own. It should have continuity in the 10-25ohm range. And no continuity to the mounting 'puck' or engine block.

 

After researching last night, that's my first thot as well. Its 9* out, so that's all gonna have to wait Thanx my friend