Legend has been brewing for years about a mythical "master key" that worked to start forklifts, pettibones (all terrain-forklifts), scissor lifts, boom lifts, golf carts, and gators. Most of the stories I've heard were at the bar, not on the jobsite, but I have heard it mentioned here and there at work.
While it is noted that most of the equipment you get from the rental yard is garbage, and will start with a flat screwdriver, the story goes that a certain key will start every new piece of machinery that they ship out, and many more.
For years I laughed in their faces, "What key is this you speak of (burp)... I have seen no KEY! (laughter)
But alas, fortune has bestowed upon me, the legendary key. I found it when I locked my tools up for lunch in the Kohler ATS I was installing (one of seven on the job). Don't worry, this isn't an advertisement for Kohler, they can lick my balls. I noticed the piece of gear was lockable, and had two keys glistening in the led temp lighting, so I selfishly took one into my own inventory with a grin.
Soon after, I forgot it was there, and was given the task to borrow a scissor lift from another trade, and run some conduit. Since nobody was around to ask, I proceeded to commandeer the SKY JACK scissor lift, but was stopped when I noticed that it needed a key. SKY JACK can lick my salty nuts. In a futile attempt, I tried the few keys I had that of which I had no idea what they did. SUCCESS! It didn't feel like it engaged any lock-pins at all, it just turned the bolt. It was the ATS key.
The key itself didn't look like it had come from a new piece of switch-gear at all, it looked like a shaved down thief's tool. All the ridges were rounded. I am not a lock smith, but the key looked shady.
Anyway, it turns out this key has worked in any job vehicle and brand that takes a small 1-1/2" long key. It says "southco" on it, and has been a lifesaver, well more like a time-saver, and in a few cases, a dangerous distraction. If you find one of these keys, do not touch it, it's not worth it man!
The key part of this story is that they key part is true. I made up all that legend stuff. Anyway, if you read all of this, that means you have as much time as I do, and God help us all. Happy trails!