i have a 2013 chevy 1 ton dually, doesel of course. after plugging in my block heater over night, it seemed hard to start. up untill now everything seemen fine. i do have 120 volts at my plug in.
When the power to the block heater first kicks on, can you listen carefully near the radiator and hear a popping or sizzling noise indicating that the heater is actually warming up?