Outside power outlet use?

The electric outlet is the male end. Yes. If it goes to the block like you say. It most likely is a heater for your water jacket. IF the wire goes to the oil pan than its a, you guessed it, oil pan heater. My block heater plug is under driver door and my oil pan heater is just a cord end behind front bumper. Good luck.

 

Mine is for the shore power system. The inverter becomes a battery charger when plugged in.

 

I plugged in my shore power and fan came on for inverter and display has flashing green lamp on bunk display with “bul” message that switched to “A65”. Don’t feel comfortable with any of it, so I unplugged.