Hot Rods My heater works but the dash vents and defroster doesnt on the olds wagon

Everything comes through the lower heater part on the floor. It wont switch over to the dash vents or defroster vents . Is there some kind of vacuum control I should be looking for that's not working?All the cables seem to be working. Any ideas? Thanks and MERRY CHRISTMAS to you all Bruce.

 

How about the other end of the cable that attaches to the door in the heater that directs the air flow. I have had them break at that spot or the door itself is messed up.

 

If it's like mine, the cable that you pull for the defrost can only be opened half way like the temp controller on that circuit. I think it shares a flap. Like wraymen stated, I would check the box end of the cable.

 

Bruce is it on the 72 wagon? My cutlass did the same thing years ago .Small vac hose to a vac switch on the heater control was leaking. control lever has a a rotary vac valve (switch) that controls the vents. Small leaks (that you may not hear) wont let the vac cans close the vents. Also the rotary valve (switch) can leak .
Just trying to remember what I did to repair it . If I think of it I will let you know.
RTP

 

Are the doors cable actuated? Or vacuum? Or electric? You'll probably need to pull the HVAC box out to have a closer look at how it works.

 

Thanks for the tips guys I will check them all out. Bruce.

 

Did one (or more) of the flex-hoses fall off?

 

bruce
I strongly recommend getting a factory shop manual for your olds(ebay?)!! it makes it SO much easier to figure problems like this without any guess work!!
merry Christmas!!
jim

 

I would bet $ on the rotary/vacuum switch behind the control panel. Changed several over the years on a # of GM products. Never fixed one just r&r'd as they were cheap.

 

Hey Bruce check for a vacuum hose disconnected or split on top of the heater box behind the glove box. Also while your looking have someone move the levers for the temp and the floor/defrost/A/C if equipped. have a look at them to be sure they are moving all the way open and closed. Joe

 

Thanks again for all the tips guys .As soon as my granddaughter{she 6} and I get the sound deadner layed down on the floor I will check it .Thanks.Bruce.

 

Heck with the seat out of the way, it will make it much easier to trouble shoot Bruce! Joe

 

Check for blockage of the tubes, I have found mice nests in them before.

 

Hey Joe maybe you got a point there! lol.Bruce.