Borderlands 2 No Vacancy mission can be triggered by finding the note from the owner of the Happy Pig Motel (which is actually an ECHO recorder held with a knife on the panel of the bounty board) in Three Horns Valley.
While Borderlands 2 No Vacancy is a short optional mission, it is a mandatory one, because by finishing it we activate the electricity back at the motel, so we can use the vending machines and the bounty board there.
You found the abandoned Happy Pig Motel. Scooter has asked you to turn the towns power back on so you can use the motels vending machines and bounty board.
Item: Skin Customization
Experience: 791 XP
First of all, we activate the steam pump thats right near the motels door. That does not work the way it should, so Scooter tells us to go and find some replacement parts at the other pumps around the hotel.
By going to the nearest waypoint we can collect the steam valve, but its on top of the pump. In order to reach it we have to shoot the ladder (glowing green) and climb up on the pump. On top, we quickly press the action button as the piston goes down to grab the first required part.
Getting the steam valve spawns some enemies from the shack below, so its easier if we deal with them from our current position.
Then we have to travel south to get the capacitor. Near the broken pump well probably find some skags, and its a good idea to kill them using our vehicle, before getting down to open the capacitors door on one of the pumps sides.
Opening it reveals the fact that is actually empty, because the skags ate it. We kill all of the newly spawned enemies (easier if we get back in our vehicle), and then we search if one of them dropped a capacitor.
Next we move north, to the last waypoint (near the exit to Three Horns Divide).
Upon arriving at our destination, Scooter tells us to kill the badass bullymong that made his lair on the top of the pump, in order to receive our last part, the gearbox.
Now we can go back to the motel and install the replacement parts. The first one is right at the bottom of the pump so its quick and easy to install.
For the second one we climb on the roof using the ladder to our left, and then we climb the pumps ladder to reach the top and install the last part.
Finally, we can get down and turn the valve on to activate the pump and restore the power.
We turn in the Borderlands 2 No Vacancy mission at the bounty board, so we can get another one, named Neither Rain nor Sleet nor Skags, which is a failable mission, and another part in our complete Borderlands 2 walkthrough.