Since there is a nice cold snap out here in E Washington, I plugged my truck in. Now I'm wondering how to tell if it is working. For some reason, the plug doesn't want to completely plug into the cord and I'm worried that my truck won't start in the -6 weather we're having.

 

the easiset way is to feel right around the heater and see if its warm. I know when mine is working when I start it ans it fires right up like its already been running. Another way you can sometimes tell is when you plug it in if you get a little spark or snapping noise from the plug and sometimes you can hear the heater when it first starts

 

When my truck has been plugged in, the temp gauge registers about 1/2-way between the lower end of the "normal" range and the bottom of the gauge.

 

Just before I shut off the truck for the night I put switch on defrost. I know the block heater is working because in the morning my window has little to no ice on it while all the other vehicles around are iced over. Never have to scrape ice! Plus the engine compartment is warm and it cranks right up.

 

Your truck should start down to -20F without being plugged in. Mind you, you probably need 10-30 oil or synthetic to do that. The plug itself will probably feel warm itself after a few minutes. If your hearing is better than mine is, you might be able to hear the block heater sizziling. You also might hear some crackling when you put the plug in.

 

Thanks guys. I could hear it sizzle last year, but this year I can't hear it so I was wondering. It worked because the truck fired right up as though it had just be shut down. It was way cool to see what a big difference it was compared to warmer (relatively) temps and not plugging it in. FTE rocks!