Originally Posted by Shibodo
I don't know where I got this, but I have in the back of my mind that the block heater only runs for 60 minutes then shuts off automatically. Gotta check the book when I'm off work.
The block heater is a simple electric cord leading to a heating element immersed in engine coolant. I am not sure on the JGC, but they are usually installed where a frost plug would go in the engine block. It will heat as long as it is plugged in. I use an external timer on mine to come on in the morning 2 hours before I leave for work.
I have not used the block heater on my new GC yet, but on my previous car you could hear a sound like a kettle of water just before it comes to a boil when the block heater was plugged in. For those of you that use this, if it is quiet enough can you hear a similar sound? If so, it would help to diagnose if the block heater is working or not.
Failing that, a simple continuity test with a multi meter across the two prongs of the plug should tell you if there is a circuit or not. I will check mine and see what the resistance reads as a point of reference for others.