I found this picture of my first van, a 1970 Econoline. I was stationed at Elizabeth City N.C. Coast Guard Aircraft and Overhaul Center. The year was 1972, I was 22 at the time. It was a wonderful time in my life when I had freedom to roam. Note the little square appendage toward the rear bumper. Even back then I had it wired for 110V. That's a household receptacle in a water tight box. I had a cord with male connectors on both ends to plug it in. Not the safest method, but for what was available at that time for someone with no money, it did work.