AC heaer box linkage adjustment???

[ws27]

Has anyone ever adjusted the linkage on a heater box for a 66-67 b-body? I've been working on a 67 Belvedere for a while, I upgraded all the underhood parts, rebuilt the vacuum switch, and now it won't switch to heat until you go to defrost. All the vacuum lines are correct and I used the vacuum schematic to confirm that vacuum is applied to the correct actuators in each mode.

I think the damper for the heater mode is not adjusted correctly. The manual is horrible for this adjustment procedure. It literally says apply vacuum to two actuators, then apply pressure (who knows where) to the linkage until A,B,C (not sure exactly which levers are A,B,C) then tighten adjustment screw (again not sure which screw)!

I'm hoping someone may have been through this nightmare before, if not once I figure it out I'll post it here.

There are three shafts connected to dampers with two actuators. So in essence, there are three functions being controlled by two actuators and some complicated linkage!

here's a pic of a guinea pig box I have laying around to experiment on:

 

[ws27]

OK, two nights to figure out this one. The manual picture is backwards.

If you look at the picture, ignore the fresh air door with the diaphragm rod pointing towards you. You will see two other diaphragms, one on top that is angled, and one lower that is roughly straight. In the manual, you can clearly see a straight (OK, not quite straight, but clearly lower) lower one and angled upper one, they are backwards. Once you figure that out, and muddle through the tubing maze, everything will work.

For the record, both of my books, one Dodge and one Plymouth were printed in 8/66, so there may be a newer version that this was fixed.

I hope this helps someone not waste the time I did making things work!

Good luck.

 

[Jim 68cuda]

w..........T........F.........

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[ws27]

That about sums it up!