300SDL (126.125) L6-3.0L DSL Turbo (603.961) (1987)
7.
To check pressure switch, proceed as follows:
a. Disconnect switch electrical connector from engine compartment near left headlight.
b. Connect a suitable test lamp between 12 volt power source and pressure switch electrical connector.
c. Test lamp should light when system pressure is below switch cut-out pressure.
8.
Move adjusting switch to ``M'' position to release oil pressure, then remove pressure gauge.
9.
Check system oil level and correct as necessary.