How can you tell for sure that your block heater is working properly?

 

i can hear a "humming" noise coming from the area of the block heater when i plug it in and i am very quite and listen. easiest way it to plug it in for an hour or so and then feel the passenger side head/valve cover. if the heater is working then the head/valve cover will be warm.

 

Thank you I will try that

 

Like Eric said, I can hear a faint 'sizzle' after it's been plugged in for a bit. I also see a spark at the plug in when it makes contact with the extension cord....

 

I just had to troubleshoot mine. I use a ohm meter to check for continuity. Your resistance will vary depending on the wattage of your heater, but they all should have continuity. I check mine at the plug and got nothing. I then unplugged the cord from the heater and ohm'd the heater. Had continuity. Pulled the cord and found a bad spot. Repaired it and now I am good to go.

 

No warmth guess I will have to check the cord tomorrow.