Vacuum Switch
Disconnect wire connector. Disconnect vacuum line and attach vacuum pump. Using an ohmmeter, check for continuity between Blue and Green wire terminals. With no vacuum applied, continuity should be present. With 6-8 in. Hg applied, no continuity should exist. Increase vacuum to 9 in. Hg and slowly release vacuum. Continuity should exist when vacuum reaches 5.5-6.2 in. Hg.