Yes, it is a 12 volt system. The adult beverage that I was having made my answer imcomplete. The 2 air heater elements each draw 95 amps at 12 volts each..

 

lol its ok.

 

The owners manual (the thing under the extra ketchup packs in the glove box) details what temperature the grid heater comes on and for how long and that once you rev the engine over a certain point it will turn off. It is also 12 volts as has been pointed out. Dimming of the head lights is normal.