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.
Was the engine warmer than not plugged in? Block heater afaik is not tied into the operating systems. It either works or it doesn't. But gotta be more specific if looking for recommendations.