Volkswagen Passat 1995 Repair Manual page 61

Manual A/C
http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW.B4.HA01.87.2
Fig. 2 A/C pressure switch -F129-, checking
Visual check: Ensure that O-ring (color: red) 10.8
mm x 1.8 mm is seated in groove
Switch part between contacts -T4a/1- and -T4a/2 of
connector housing switches magnetic coupling -N25-
off when refrigerant system insufficiently filled or
pressure too high.
- Opens below 1.2 bar (17.4 psi) and closes again
above 2.4 bar (34.8 psi) (switching threshold)
- Opens above 32 bar (464 psi) and closes again
below 24 bar (348 psi) (switching threshold)
- Briefly bridge circuit between chambers 1 and 2
with engine running. If the compressor clutch -
N25- switches on, the refrigerant system is empty.
Take vehicle to specialist service workshop.
Switch part between contacts 3 and 4 of connector
housing
- Closes above 16 bar (232 psi) and opens below
12.5 bar (181.3 psi) (switching threshold)
Page 21 of 36
87-36
12/7/2004