Ive been pluging my truck but i dont think my block heater is working. In the morning when i go out to start my truck after its been pluged in allnight my temp gauge doesnt go up at all. I know other guys with cummins and they say theirs go up above 150. Ive checked all my relays dont know what else it could be unless it is the heater core its self. Any one know what else i could check? Thanks!!

 

If you have a voltmeter it's pretty easy to test the block heater. Check for continuity between the two flat blade connectors on the end of the block heater cord. If you don't have continuity then the cord is broken or the element itself is broken.

 

I've never heard of 150* from a standard block heater. A circulating, or Espar Yes, but not a standard block heater.

Feel around the block heater itself for heat. Also, sometimes when you plug them in when it's cold you can hear a slight crackling sound after 10 seconds or so.

 

I will check that thanks!

 

Yup,i use to hear the crackling after plugging in. I had to change mine recently.And as for heating to 150 degrees, mine didn't get that hot. Plus i could tell because my motor didn't idle good after start up.
There not hard to change.