heater vaccum hose question

[Gregsenne]

I know this question has been asked a million times but Im having problems finding the answer.

I have two vaccum lines dangling below my dash. One is black with a blue stripe, one is black with a tan stripe. Where do they go?

I *think* the blue one goes to the actuator on the other side of the heater box sandwiched against the firewall. Where does the other one go? The defrost actuator by the gas pedal is hooked up, and so is the fresh air actuator on the pass side kickpanel. I don't know of any other actuators inside the truck

Thanks

[Ski-me]

I think the Tan one goes to the AC actuator and the Blue one goes to the heater actuator.

[85gmcguy]

One should go to the "blend door actuator" next to the firewall and one to the "recirculator door" above the plastic panel on the passenger side kick panel. At least that's where the ones on my '85 go.

[Gregsenne]

Ok so I think the blue one goes to the blend door actuator, which is behind the heater box up against the firewall. I just got the hose on there, and man, that was hard to get to!

I'm also pretty sure the tan one goes to the AC actuator. But where is it? I am trying to feel around and can't find anywhere for it to go to. Can someone point me in the right direction?

There is already a line on the recirculator door (its orange) and it has a tee that also goes to the actuator in the cowl.

Thanks

[Gregsenne]

Update: Im pretty sure I found the port sticking off the side of that blend actuator. Can someone confirm that blue goes on the outside of the actuator and tan goes in the center? Or that I even have the right ports!

Thanks

[chengny]

[Gregsenne]

I hooked it up this way (tan on the center, blue on the outside) and everything seems to be working great this morning and switching properly between floor, vent, and defrost.
Thanks!

[Gregsenne]

For anyone else who is completely confused, like I was, especially after looking at the diagram (previous post), I think I have figured it out. I'm confused on why the blue and tan lines are called heat and air conditioning, when in reality they run to the actuator that controls the door between vent and floor/defrost. If there is vacuum on the tan line, it pulls the door in so that air is diverted into the ducts that run to the vents. If there is vacuum on the blue line instead, the door is pushed out so that the air goes into the ducts that go to the floor and defrost. Defrost is then further controlled by the defrost actuator. So I think these lines should be called floor and vent, rather than heat and ac, because it had me confused for a while. Heat and AC is controlled by a blend door that is cable driven, not a vacuum actuator.
I am also confused by the Vent/Vacuum/Optional designations in the chart. They don't seem to follow the way my truck operates. For example, the chart lists that the OSA/REC (Outside Air/Recirculator) port has vacuum in the off, heat, and defrost positions, when in reality it is only changed when put into MAX AC mode. I tested all my vacuum lines, and watched which actuators opened and closed when put in each position, and here's what I got:
Off: blue. Max AC: Tan and Orange. Norm AC: Tan. Bi-Level: Nothing. Vent: Tan. Heat: Blue. Defrost: Black and Blue.

[chengny]

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