Heater always on - need guidance

[DJB]

My 86 has the automated heating system, now that summer has arrived in Sydney, I would like to fix the issue that hot air constantly comes out of the foot-well vents when the heater is off.

The automated control actuating arm is working and changing the position on the dial pulls the lever and works both flappers. The flappers are almost fully open when the heater is off.

What stops the heat from moving forward when the heater is off, is there some internals in the flapper boxes that also closes in the off position?

I haven't yet checked the resistance settings of the automated controller at position 5 but will do that. Also the foot-well blowers are not operating when the problem is occurring.

I have also tried disconnecting the main engine blower, but still the problem occurs.

Any guidance would be appreciated.

[47silver]

if the flapper is like my 75 then on the outside of the flapper is a round mechanism with pie shapped cutouts and on the inside of the flapper is a damper (a round piece of metal with some type of seal on the edge) the inside damper diverts air from the engine either to the passenger compartment or to the pie round external mechanism through the slots in the bottom of the flapper... the hot air then goes into the wheel well...one my inside dampers was corroded and even though i could see the outside pie shapped device move with the cable the air still managed to dump into the passanger compartment. if you can check these with a flashlight..
if you have to replace them search this site for some good info as they are not fun to replace.

gary

[DJB]

Thanks Gary,

Has anyone every pulled these flapper apart, or can that not be done?

Any thoughts or advice welcomed.

[DJB]

Any advice?

[fintstone]

Yes, it sounds like the flapper(damper) inside is stuck. It should close as the vents open. You could probably verify this by removing the hose and fishing something flexible down through that area or even through the pie shaped openings. The valve should close and block heat flow when those vents open to vent it. You may be able to lubricate it enough to get it moving, but I suspect you will probably have to replace it if it is very rusty. Here is an informative link: http://www.pelicanparts.com/techarticles/tom_sharpes/heater_box1.htm

[DJB]

Thanks Flinstone - sounds like another job for the holidays.