Block heater question?

[Grassland]

My wife's old 97 civic the block heater shorted to the block I guess, it would trip the GFI about a second after being plugged in. Super convenient when it was -30.
Didn't start well without the block heater in that weather.

And let's be honest, if you are going to hear about somebody complaining, it will probably be me lol

 

[Joe917]

Similar thing here with a prior truck.
Its heating element leaked, conducting to the coolant.
Between its chassis and earth was about 70V.
But being connected to GFCI but ungrounded. Under a dry carport it would not trip a GFCI.
Eventually discovered when it was plugged into a 100’ cord at different location.
Even with good ground connection it would mildly shock.

The coolant heater in my International Harvester will trip a GFI every time but works fine on a regular plug. Pretty typical of in line coolant heaters.