Vacuum Control Solenoid Valve Electrical Signal

Fig. 10 Vacuum routing:

1. Start engine and allow to reach normal operating temperature. Shut engine off.
2. Connect a suitable tachometer to engine, then connect a voltmeter to vacuum control solenoid valve terminal coupler (orange coupler).
3. On automatic transmission equipped vehicles, place selector lever in "Park" position.
4. Start engine and allow to idle. Current should flow to solenoid valve.

NOTE: On automatic transmission equipped vehicles, current should stop flowing when selector lever is shifted out of "Park"

5. Increase engine speed to 2000 RPM, then slowly decrease speed and observe when voltage begins to flow to terminal. Voltage should begin to flow at 1000-1200 RPM.
6. Disconnect electrical coupler from No. 1 water temperature switch, then connect a jumper wire to terminals in coupler.
7. Pull out choke knob and increase engine speed to 2000 RPM, then disconnect electrical coupler from No. 2 water temperature switch at radiator. Observe voltmeter. Voltage should stop flowing to solenoid valve terminal.
8. Disconnect jumper wire and reconnect No. 1 water temperature switch coupler, then accelerate engine to 3000 RPM. Allow engine to decelerate and observe voltmeter. Current should start flowing and continue to flow during deceleration and at idle.