HVAC Air distribution problems

[Whit52]

1987 V20 Suburban. Replaced leaking heater core. Then discovered, after installation of heater distributor box, that hvac air distribution is all wrong. Heat comes out of a/c vents. A/C and defrost comes out of lower heat vents. No air out out of defrost vents. Did I misplace vacuum hoses on the two actuators? One vacuum hose goes on defrost actuator at driver's end of distribution box. Hard to misplace that hose as it is far away from the AC/Heat actuator located at back, middle of box. This actuator has 2 ports. I placed blue/black hose on port closest to driver, and a brown/black hose on the other port. Also, reinstalled metal cable on top of box. What have I done wrong?

 

[Snoots]

Give this a try.

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[Sad Sack]

@Snoots
Nice diagram, what years does that cover?

 

[Whit52]

Thanks for the input. However, that diagram is for a G20. The setup for the V20 is completely different. I took off ducting and ran through hvac options, watching action of blending doors. All function. But the middle one, actuated by the heat/ac vacuum actuator with 2 ports, moves in the exact opposite direction needed, given the ducting layout, to have the ac and heat go to the right path of ducting. Hence, my thought that the two vacuum hoses on that actuator need to be switched. Thoughts?

 

[Snoots]

@Snoots
Nice diagram, what years does that cover?

I really have no idea.

 

[Snoots]

Sounds reasonable.

 

[Whit52]

Well upon removal of heater box I found out that after heater core replacement I switched the 2 vacuum hoses on the 2 ports of the ac/heater actuator. So, upon re-switching back to correct positions (blue on driver's side, tan on the right side) everything works as designed.

 

[maplec10]

Hello, so tan/black hose closest to driver and blue/black on other port?

 

[Whit52]

No. The blue/black striped vacuum hose goes on the port closest to driver and the tan/black stripped vacuum hose goes on the passenger side port. These 2 ports are on the vacuum actuator in the middle of the heater/ac distribution box. A black vacuum hose goes on the actuator closest to the driver. This is for the defrost.

 

[maplec10]

Dude thank you so much. Guess previous owner had them switched around. I had been fighting this couple weeks. Working now but that inside plastic baffle is broken so keeps spinning freely and blocking mode door.