I salvaged an old oxygen concentrator to get the small compressor out of it. The pump is a devilbiss ZW370D14 and can be used as an compressor or vacuum pump. I'm not only a newbie, but I am electronically challanged. My pump has four wires going to it out of a wire harness. I have no idea what happens to the current from the 120v going into the compressor before it connects to the 4 wire harness leading to the motor. I checked for current while the coconcentrator was running and found one 120v energized wire and one neutral, the other two showed no current. When I disconnected the harness and connected a live + and - to the same live wires I had identified, the compressor does not come on. I found a pictue of my exact motor for sale on another website with a mystery capacitor or coil leading from the 120v line tothe motor. Can anyone tell me what the mystery gizmo is so that I can get my compressor working. Can you please dumb down your advice for a newbie non electrician.