From '98 service manual:
High pressure switch
The function of the high pressure switch is to protect the high pressure section of the refrigerant circuit. When pressure exceeds the maximum value of 2965kPa (430psi) because, for instance, the air flow through the condenser is impeded or the high pressure line is blocked, the high pressure switch switches the compressor off.
Only when the pressure has fallen once more to 2241kPa (325psi) bar is the compressor switched on again. At a pressure level of 2241kPa (325psi) the PCM switches to high blower speed.
Only when the pressure has fallen once more to 1717 kPa (249 psi) does the PCM switch to low blower speed.
