Question on vent air flow issue

[ScottH]

On the 87 I recently bought I just found that the air only blows from the heater duct, not from the vents, regardless of the setting. Did some investigating and it appears that the flap that controls the air flow is not working properly. I removed the glove box and I can move the rod on the evap box but it will only stay in the heat position when the blower is on. I cant tell what it attaches to on the other end.

Can anyone tell me what attaches to the rod that directs the air flow?

Any help is appreciated.

Thanks
Scott

[Just call me Sean]

Temperature control is cable, vent controls are vacuum.

[ScottH]

thanks for the info, guess I'll have to look into it further.

Can anyone tell me where the vacuum for the AC/Heat originates?

[Just call me Sean]

From the engine vacuum tee on the intake.

[chengny]

When diaphragm 53 strokes, it directly moves valve 171 and also valve 163 via connecting link 153:




The positioning of these two "valves" is what varies the air flow between the dash vents and the floor outlet. If your "link" is adrift, your system won't shift between the two.

[ScottH]

Thanks guys....traced the vacuum line and found it was broken.
Did a quick fix on it & it looks like it solved the problem.

Appreciate everyones help.

Scott