QuestionHello, I have a 2002 Ford Explorer -- V8 4X4. When I turn my ac to blow threw the vents, it only blows out the defrost and floor. There has been very few times it actually worked correctly but as soon as i turn my truck off and restart it, it no longer will blow air out of the vent. Any help will be greatly appreciated. Thank you.
AnswerHi,
The mode control on a 2002 Ford explorer is a vacuum controlled actuator in the HVAC box that controls the direction of flow based on a vacuum direction control switch.
First the supply vacuum to the control head needs to be checked. If you pop the hood there is a black plastic vacuum line that runs into the passengers side of the vehicle near the evaporator box. Make sure this line has an adequate supply of vacuum from the engine.
Second is the diaphragm inside the actuator. If you can find the actuator, select vents, and disconnect vacuum line to actuator and see if there is suction there.
Most common problem : inadequate vacuum due to plugged or broken lines (they get brittle from heat) easy fix
Second most common: defective blend actuator. Not a terrible fix
Third common: broken flap actuator or linkage inside HVAC box. Not common but I have seen it twice. Very difficult repair as dash needs to come out to facilitate removal and dis assembly of HVAC box. Sometimes you can't even buy the flap you have to buy the whole box in which case I have purchased used ones from auto wreckers and carefully inspected new flap.
Wayne
