as a point of information...
to test continuity of the switch:
With the switch in the center position,
set your meter to Ohms (RX1)
put one lead on Terminal A, then test each other terminal and record your readings.
put on lead on Terminal B, then test to each of the other terminals and record the readings
Some (most) switches are center off- there should be no continuity between poles.
on your switch, the A & B terminals are the main poles. (but, other poles may be utilized to achieve the same function)
to test the functions of the switch:
switch the switch in either direction
put one meter lead on switch Terminal A and test to the other terminals , you may get continuity on terminals 4 and 1 or, on terminals 2 and 1, respectively in relation to direction chosen on the switch throw
put one meter lead on switch Terminal B and test to the other terminals, you may get continuity on terminals 2 and 3 or, on terminals 3 and 4 respectively in relation to switch position