Volkswagen Passat 1995 Repair Manual page 94

A/C refrigerant system
http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW.B4.HA01.87.4
A/C pressure switch -F129-
The A/C pressure switch is a combination switch (two
switching components) that protects refrigerant circuit
components from malfunctioning due to excessive or
insufficient refrigerant system pressures.
Switch part between terminals 1 and 2 switches
off the A/C clutch -N25- when the system
pressure is too high or when there is not enough
refrigerant in the system .
Switch part between terminals 3 and 4 switches
coolant fan -V7- to the next higher fan speed
when system pressures increase.
Page 7 of 7
87-68
12/7/2004