The first thing I notice is that the pressure switch values are reversed. The pressure switch is normally closed, and opens when the system pressure reaches 115 psi. So I would change your code like so:
Code:
If high_pressure = 1 THEN compressor_go_on
If high_pressure = 0 THEN compressor_go_off
(I think I would also change the pressure switch alias to low_pressure instead of high_pressure.)