Hello. We have owned this truck less then a year. I have a question. There is a A/C plug running out the front of my bumper. It runs into a wire cluster that runs to the battery. There is no plug hooked to my block heater. It is missing. All I can find is a video on you tube that a man has the same thing and claims it is for the block heater. Does anyone know what the purpose of this plug is ? This is a 2007 Chevy Duramax LBZ. Classic. (Allison).

 

Figured it out.

 

@MNS79 please tell us the answer!!