Three-Way Solenoid

On 1976-78 models, power to three-way solenoid is controlled by coolant thermo switch. When coolant temperature is below 109°F (43°C), the switch will close and energize three-way solenoid. This will close vacuum passage to EGR valve. When coolant temperature is above 122°F (50°C), the thermo switch opens and de-energize three-way solenoid, allowing vacuum to reach EGR valve.

Used on all 1979 models, except California 2.3L engine. The solenoid on 2.0L engines is electrically connected to engine speed switch and is energized to open and allow vacuum to pass normally when predetermined vehicle speed is reached. On Federal 2.3L engines, solenoid is connected to choke control knob. Position of choke knob determines whether solenoid is energized or not.