A/C woes
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
There is a maze of ductwork in the dash that has several doors that open/close to direct which vent to send the cold air to. These operate with a vacuum servo that can fail or stick and not seal the door. There is also a blend door that mixes cold/hot/vent air.
Also, I have seen the intake duct thru the wiper screens end up plugged with leaves and trash so badly that air cannot flow thru the evaporator and even get to the cabin. If the blower motor is running at high speed, you can pull the motor and look inside the housing to see if there is lots of trash stuck in there.
Otherwise, run the a/c on high and feel around all the vents and along the floor ducts to see which are leaking the most air. Then you can work toward the duct-door thats at fault.
Leaking vac hoses might also not allow the servos to operate fully.
Thread Starter
Racer
Joined: May 2006
Posts: 358
Likes: 0
From: Laredo Tx
You're probably loosing half the fans volume to leaks in all the vents. If each vent door leaks just a little, you only get about half to the cabin vent.
There is a maze of ductwork in the dash that has several doors that open/close to direct which vent to send the cold air to. These operate with a vacuum servo that can fail or stick and not seal the door. There is also a blend door that mixes cold/hot/vent air.
Also, I have seen the intake duct thru the wiper screens end up plugged with leaves and trash so badly that air cannot flow thru the evaporator and even get to the cabin. If the blower motor is running at high speed, you can pull the motor and look inside the housing to see if there is lots of trash stuck in there.
Otherwise, run the a/c on high and feel around all the vents and along the floor ducts to see which are leaking the most air. Then you can work toward the duct-door thats at fault.
Leaking vac hoses might also not allow the servos to operate fully.
There is a maze of ductwork in the dash that has several doors that open/close to direct which vent to send the cold air to. These operate with a vacuum servo that can fail or stick and not seal the door. There is also a blend door that mixes cold/hot/vent air.
Also, I have seen the intake duct thru the wiper screens end up plugged with leaves and trash so badly that air cannot flow thru the evaporator and even get to the cabin. If the blower motor is running at high speed, you can pull the motor and look inside the housing to see if there is lots of trash stuck in there.
Otherwise, run the a/c on high and feel around all the vents and along the floor ducts to see which are leaking the most air. Then you can work toward the duct-door thats at fault.
Leaking vac hoses might also not allow the servos to operate fully.
