EA2-3NJ Relay won't switch, what am I doing wrong?
This kind of small relays are frequently have pre-polarized primary coil, to reduce the switch effort. And there could be a flyback diode inside as well. The datasheets show the bottom view of relays. And the application section states,


  If the internal connection diagram of a relay shows + and − symbols on
  the coil, apply the rated voltage to the relay in the specified
  direction.


So, if it doesn't work, it is likely a misunderstanding of relay pinout, just try the opposite polarity.