Vacuum Switch

Fig. 77 Vacuum switch test connections:

1. Disconnect vacuum lines and wiring harness connector from vacuum switch and remove vacuum switch from vehicle.
2. Connect voltmeter to vacuum switch as shown in Fig. 77.
3. With no vacuum applied to switch, meter should read battery voltage.
4. Apply at least 6.3 inches Hg. of vacuum to switch. Meter should read 0 volts.
5. If readings are not as specified, vacuum switch is defective.