My 2006 has a factory installed block heater. I am located in Ontario and the block heater did not work this past winter. It appears to be a power cord problem, as I understand there is a thermostat in plug end which will not activate until the outside temp is at -18d C is this correct, can I remove this plug and replace with a conventional plug and use a timer to control the block heater

 

I don't know if it is in the plug but it would be worth a try. Doesn't the cord plug into the heater? If so you could replace the cord.

If you have used the heater for 7 winters, the heater itself could have failed. If the cord plugs into the heater you could check the resistance on the heater terminals.