Mustang L4-140 2.3L Turbo VIN W FI (1984)
Thermostatic Air Cleaner Vacuum Switch: Description and Operation
Cold Weather Modulator
Fig. 3 Cold weather modulator
This modulator, Fig. 3, is used on some models to prevent the air cleaner door from opening when outside air is below a predetermined temperature.
At higher ambient temperatures, the modulator is inoperative. During acceleration, with outside air below the preset temperature, the modulator will
close off the vacuum to the motor and hold the duct open. The modulator is located inline between the air temperature control sensor and the vacuum
duct motor.