SL 600 (129.076) V12-6.0L (120.981) (1995)
Refrigerant Pressure Sensor / Switch: Testing and Inspection
Pressure Switch S31/1
TESTING PROCEDURE:
1. Switch on ignition and air conditioning system.
2. Using a voltmeter; connect positive lead to battery and check negative terminals one after another at the two connections on the pressure switch
(S31/1). If only one terminal is connected to ground, the air conditioning system is either not sufficiently charged or the pressure switch (S31/1) is
defective. If ground is present at both terminals and the refrigerant compressor does not switch on, check compressor switch-off.
3. To check the refrigerant level; allow engine to run at idle and bridge the two terminals on the pressure switch (S31/1). Observe observation glass
on fluid reservoir to determine whether refrigerant flows without bubbles after refrigerant compressor switches on. recharge air conditioning
system if required.
TEST DATA:
Pressure Switch (S31/1):
Switch-off pressure: 2.0/30 bar gauge pressure
Switch-on pressure: 2.6/22 bar gauge pressure