ive got a 1971 d100 with factory air.i replaced the ac push button switch and new blower switch,but cant get but a very small amount of air or heat from it seems somethine is stoped up. the blower motor works on all three speeds.
any help .
bert king
montgomery,texas
Ac Vent Help.
Re: Ac Vent Help.
If ducting is original it may look acceptable,but can have tears on the sides you can't see,or maybe loose.gp
Re: Ac Vent Help.
bert thers a little door like That might not be opening or closeing right , you have to reach up in there & feel it , I think it's vacum run
Dave
Dave
cowboy Alvin Tx
67 w100 318 3spd
2005 Ram 2500 CC Diesel 4x4 lwb
LAND OF THE FREE
BECAUSE OF THE BRAVE
67 w100 318 3spd
2005 Ram 2500 CC Diesel 4x4 lwb
LAND OF THE FREE
BECAUSE OF THE BRAVE
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nfury8
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Re: Ac Vent Help.
No air out of any vents? or just the dash?
Was it working at all before the buttons were replaced,
or any point in the memorable past?
There are 3 outlet modes.
-Floor
-Windshield
-Dash
If the blower is running air should be coming out at least one of these places.
If not, there is a problem either in the blower or the box, possibly a blockage.
Run through all the push buttons and see if you can detect air coming from any
of the outlets or under the dash. Under the dash would point to a bad hose.
As you are running through the buttons, listen if you can hear any of the vacuum
actuators operating. Every button should activate at least one of them.
There is one vacuum actuator that controls the air source, either from in the cab
or the cowl. It is always open to the cowl, unless MAX AC is selected. It sets on top
of the blower shroud and is accessed through the glove box, when the liner is removed.
The next actuator is on top of the box, and easily accessed if the radio and heater
controls are removed or through the glove box opening also. It controls the flow of air
into either the heater core or the evaporator. The heater or is the rear and the
evaporator is the front.
The third actuator is on the back of the box, on the left side. It can be accessed from
the floor, it is behind the drivers vent tube and controls the mix of air to the windshield
and floor. The heat outlet is on the bottom left also.
If the Heat/AC actuator is working properly, you should be able to get air to come out the
center dash vents in AC mode or the floor vent in Heat Mode. The floor vent uses no duct at all,
and the dash tube is only 3 inches long. They both vent air directly off the core or evaporator.
There is plate under the dash, directly under the center dash vents, held in place by 4 small
screws. If that plate is removed, you can access the dash vent tube for inspection.
Here is my guess- The mode door, inside the box is stuck. It is about 8 inches square,
and was covered in foam on both side. Is pivots on one point, visible as a small rod sticking
out the bottom of the box. The door swings very close the floor of the box. The foam on
my box was completely desintegrated and gone. A piece of foam or other foriegn material,
leaves, critter nest... may have it jammed. If it were stuck mid way, it would split the air
between the 2 sides and neither would get full air.
It is possible that there could be a problem in the vacuum lines between the controls
and actuators, but that air is still going somewhere.
If you haven't had your box out, I would HIGHLY recommend you do so if you plan to make
good use of your heat and AC. There are a lot of places in there for stuff to get stuck and
cause problems. Unfortunately, that means removing the whole dash. The box is attached
the firewall in 5 places and the dash frame in 1. There are 3 bolts in the engine bay, a bracket
connects to the cowl, near the wiper motor and another on the lower right of the cowl.
The dash bracket is on the lower right, of the dash vents.
I just went through a complete rebuild of my box, and have a bunch of pictures on my Picasa
gallery. They should offer you some good reference. Let me know if you have questions.
http://picasaweb.google.com/nfury8u2/ACBox
Was it working at all before the buttons were replaced,
or any point in the memorable past?
There are 3 outlet modes.
-Floor
-Windshield
-Dash
If the blower is running air should be coming out at least one of these places.
If not, there is a problem either in the blower or the box, possibly a blockage.
Run through all the push buttons and see if you can detect air coming from any
of the outlets or under the dash. Under the dash would point to a bad hose.
As you are running through the buttons, listen if you can hear any of the vacuum
actuators operating. Every button should activate at least one of them.
There is one vacuum actuator that controls the air source, either from in the cab
or the cowl. It is always open to the cowl, unless MAX AC is selected. It sets on top
of the blower shroud and is accessed through the glove box, when the liner is removed.
The next actuator is on top of the box, and easily accessed if the radio and heater
controls are removed or through the glove box opening also. It controls the flow of air
into either the heater core or the evaporator. The heater or is the rear and the
evaporator is the front.
The third actuator is on the back of the box, on the left side. It can be accessed from
the floor, it is behind the drivers vent tube and controls the mix of air to the windshield
and floor. The heat outlet is on the bottom left also.
If the Heat/AC actuator is working properly, you should be able to get air to come out the
center dash vents in AC mode or the floor vent in Heat Mode. The floor vent uses no duct at all,
and the dash tube is only 3 inches long. They both vent air directly off the core or evaporator.
There is plate under the dash, directly under the center dash vents, held in place by 4 small
screws. If that plate is removed, you can access the dash vent tube for inspection.
Here is my guess- The mode door, inside the box is stuck. It is about 8 inches square,
and was covered in foam on both side. Is pivots on one point, visible as a small rod sticking
out the bottom of the box. The door swings very close the floor of the box. The foam on
my box was completely desintegrated and gone. A piece of foam or other foriegn material,
leaves, critter nest... may have it jammed. If it were stuck mid way, it would split the air
between the 2 sides and neither would get full air.
It is possible that there could be a problem in the vacuum lines between the controls
and actuators, but that air is still going somewhere.
If you haven't had your box out, I would HIGHLY recommend you do so if you plan to make
good use of your heat and AC. There are a lot of places in there for stuff to get stuck and
cause problems. Unfortunately, that means removing the whole dash. The box is attached
the firewall in 5 places and the dash frame in 1. There are 3 bolts in the engine bay, a bracket
connects to the cowl, near the wiper motor and another on the lower right of the cowl.
The dash bracket is on the lower right, of the dash vents.
I just went through a complete rebuild of my box, and have a bunch of pictures on my Picasa
gallery. They should offer you some good reference. Let me know if you have questions.
http://picasaweb.google.com/nfury8u2/ACBox