Plymouth3596
Active Member
My 87 Gran Fury when I put the AC on warm air blows out of the defroster vents I know it needs freon but shouldn't it blow out of the AC vents hot air when set on AC ?
Gran Fury AC
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Mikes5thAve
Well-Known Member
Not fully sure how that one works. If it's the same as the Chrysler one it's semi automatic with a sensor an motorized blend door that can fail and cause issues. And the vacuum lines behind the controls can get brittle and break but doesn't seem to be as much of an issue in places like NY.
I think the owners manual if you have it says what the different settings do.
I think the owners manual if you have it says what the different settings do.
Plymouth3596
Active Member
its probably a pain to get that switch panel out it always stays on defrost remember on the older cars you could go under the dash and flip the door with your hand not sure about this car
Plymouth3596
Active Member
anyway to get to it and move it from under the dash
Plymouth3596
Active Member
ok so the vacuum line that feeds the inside panel would come from the intake manifold or carb anyone know about where to look
Mikes5thAve
Well-Known Member
Little thin line somewhere going through the firewall.
Chances are if its a vacuum problem unless the rubber part where it connects to the intake is hard or split or disconnected the lines for the controls under the dash have broken up. There are several posts about that.
Plymouth3596
Active Member
thanks- so the dash cluster has to be pulled to get to those hoses
slant six
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This is likley not a blend door issue.
When I think Blend door I think of temperature control.
It could be vacuum lines underhood or under dash that have gotten brittle and failed as others have said, but I doubt it. The Vacuum servo has likely failed internally. This has happened 2x on my F body (similar to, but not the same design) as your car.
My AC would blow cold, but the servo that would close inside the heater box would not re-route air to the dash vents - It would always default to 1/2 defrost and 1/2 Heat.
To diagnose and fix, you need to use a bit of scientific method and be prepared to pull the entire dash out of the vehicle to do this job correctly, along with removing the HVAC Box off of the firewall. I also recommend getting the FSM for your year and model vehicle.
On my F body, the vacuum servo that needed to be replaced was inside the HVAC box. No access to it from the outside or under the dash.. hence pulling the entire assembly off the car, opening it up for testing a d rebuild.
Hope this helps.
Cheers!
When I think Blend door I think of temperature control.
It could be vacuum lines underhood or under dash that have gotten brittle and failed as others have said, but I doubt it. The Vacuum servo has likely failed internally. This has happened 2x on my F body (similar to, but not the same design) as your car.
My AC would blow cold, but the servo that would close inside the heater box would not re-route air to the dash vents - It would always default to 1/2 defrost and 1/2 Heat.
To diagnose and fix, you need to use a bit of scientific method and be prepared to pull the entire dash out of the vehicle to do this job correctly, along with removing the HVAC Box off of the firewall. I also recommend getting the FSM for your year and model vehicle.
On my F body, the vacuum servo that needed to be replaced was inside the HVAC box. No access to it from the outside or under the dash.. hence pulling the entire assembly off the car, opening it up for testing a d rebuild.
Hope this helps.
Cheers!
