How's this supposed to work anyway?

[240260280]

Here  is a 1973 240z heater supplement.

1973 s30 heater supplement.pdf

[jvandyke]

thanks, this is helping

According to the '73 supplement from above (thanks for that BTW!), page 6 "Mode Door" section.  This is the one that sends air either to "center vent/outboard vents" or "floor/defrost".  This is the one that is probably inoperative, I'll crawl up there and manually move it over and see what happens.  A full R&R of the system is looming, possibly including resurrecting the A/C.  I made this to help my little brain.

240zheatercontrols.pdf

Edited October 23, 2018 by jvandyke

[jvandyke]

so top slider to "Heat" and you get outside air for heating?  Seems like that wouldn't work so well, pulling in super cold air into the heater box?

[240260280]

More good pictures here: 1971 S30 Chassis Supplement V1.pdf

 

Mother lode: http://240260280.com/Docs/

[240260280]

Overview of control cable routing (correct me if I am wrong, I never decoded this stuff before).

1)  the top slider controls two flaps (red)

-a fresh/recirculate flap in the fan box

-a direction flap in the middle assembly (routes air from fan towards vents in dash  or through heater core towards floor and windshield defrost) This flap can completely close off air flow through heater core.

2) the middle slider controls the hot water valve (blue)

3) the bottom cable controls the foot area doors (green)

- when the air is routed through the heater core with the top slider, it then routes to the windshield and foot area; this slider can close off the foot area and force all hot air to the windshield

 

Controls as viewed from fire wall

 

Water Hoses, core and control wire:

 

 

 

Flap that closes off air flow through heater core and middle control wire 1 of 2:

 

Flap that closes off fresh air at glove box (control wire 2 of 2 not shown)

 

 

Floor Door flaps, internal linkage to other door, and control wire

Edited October 24, 2018 by 240260280

[jvandyke]

Awesome, many thanks. I think I've got it now.  I reached up under the dash, well, in honesty I laid on the floor (this is getting harder to do as my body complains and my eyesight can't focus where it needs to anymore, getting old sucks.)  So when I manually moved the "mode door", second of the red lines above, the one that goes to the heater box, upper left side, finally air moved to the defrost/floor vents and my kid took off, reported a bit later "we have heat".  Score.  A long way from controlling it reliably from the controls but at least it's there.  Thanks all.  I look forward to picking your brains further down the road.  I really love this car.  I should get me my own maybe.  BTW there's errors all over the manuals isn't there?  For instance, in post above, top diagram it says cable 44 is the "hot water control cable", and 41 is the temperature control cable (that's true but BOTH can't be)