82 280zx Heater box ?

[DesZ]

I've have this Heater box I'm trying to reinstall now that I've replace the Water Cock. My problem is there are 3 Vacuum valves on the left side of it and I am unsure of what vacuum hoses go to what. I have the FSM-Factory Service Manual and have even printed out the Vacuum lines schematic, but like many others can't make sense of it? The back 2 Vacuum Valves have 2 hose connectors. One on the bottom, which activate the control arms on the other side (and make it operational). The other on the side. Yet I have found no pictures (anywhere online) of what each one of these Vacuum Valves are even called.

I have a manual AC and one Vacuum hose coming thru the firewall from the engine compartment. I believe it will connect to the bottom of the Vacuum Valve at the rear of the Heater box. I've already simulated by sucking on a hose connected to it and it seems to open the main door to allow air to pass thru the Heater core.

Finally my question: Do I have that right?
Appreciate the help.

PS: I am going to take some before and after pictures and post them for others future reference.

[Wade Nelson]

The vacuum lines have stripes on them, white, yellow green, one or two to help you identify them.

Vacuum from the underhood storage reservoir goes to the vacuum selector (round thing with 8 hose barbs) "S" for source, hose with red stripe.

Yellow/ 2Y goes to the bottom, or "floor" door mechanism. If you get the two lines reversed, I'm not sure it matters, what it gives you is stage 1 and stage 2 of door closure.

The green / 2G lines goo to the fresh air intake door above the blower motor.

The white and 2 white go to the main vent door on the left hand side of the box.

The other vacuum "motor" on the left side of the box gets the plain black hose, which connects to the control switch in the lower dash panel.

The "diagram" doesn't EXACTLY show you how all this is done, for instance there was a 3-way fitting on my 2W hose to split it between the vent door, floor door, and dash knob.

I'm looking at the "Air flow and Vacuum System" diagram on page Ha-19 of my FSM.

[DesZ]

Wade: thanks for the tips but mine's a Manual not Automatic AC. I think that 8 prong vacuum selector is for automatics as I can't seem to find it? I'll post some pictures tomorrow.

[Wade Nelson]

YOu've got it backwards, the manual vacuum selector has the most "barbs" or "nipples", the automatic has the fewest.

After you remove the console/stereo you can see the vacuum selector on the bottom of the heater/AC control unit.

If you'll post some GOOD pictures of your airbox (from all angles) perhaps I'll go pull my dash down and take some pictures of what's connected where and HOW, and together we can put together a "how to" for the next schmoe.

I thought the various vacuum motors operating the airbox "doors" were bolted to the firewall, not the airbox itself. Is my memory failing?

[Wade Nelson]

Here's the money shot...

[Wade Nelson]

Annotated... red circle indicates a 4-way fitting.

The single yellow stripe was on the BACK of the hose pictured, I couldn't twist it AND hold the camera at the same time...

The actuator above the TOP of the picture (not visible) is the "bypass" actuator controlled by the little vacuum switch in the dash, below the ignition switch. Hose is all black.

There must be a single white line to the back of the vent (main) motor (not fresh/recirc) but it's not visible in the photo. Hmm, I wonder if it has fallen off...

[DesZ]

Incredible help your giving me Wade. Thank you!!! Thanks to your help I found the 6 port vacuum Selector still connected below the Heater/AC Control Unit (I never removed it nor the Dashboard). AND I was able to see the Red Striped Vacuum hose (S-Vacuum Source/Primary) which only made sense since the Vacuum hose coming from the engine compartment was bigger then all the other 6. And just the red connector had a white hose to hose jumper/connector. So I connected it and taped it up with red electrical tape so it won't come loose. But check out he next thread I'm starting about the Vacuum Valves and I got some better pictures then you since my Heater box is on the floor in front of me. Happy 4th of July!!!

[DesZ]

1982 280zx Heaterbox 3 Vacuum Valves. Two Valve connectors on the Rear two. The furthest rear one opens up the air Intake door per FSM HA-5. If I knew which vacuum lines went onto this one I think I'd have my reinstallation licked!

[DesZ]

Ok I managed to figure out the furthest back towards the firewall (valve on far left in picture above) Vacuum Valve's Hoses. Based on the FSM Vacuum diagram and the info Wade gave me above, the 2-Y (2 yellow stripes goes to the side Vacuum Valve Connector and the Y lone Yellow stripe goes to the bottom vacuum Valve connector on that furthest back bottom Vacuum Valve connector that connected manually to the Air Intake door.

[Wade Nelson]

Great picture. Any way you could annotate that with the colored arrows like I did? 2 yellow arrows = hose with 2 yellow stripes, etc. That would make it a lot easier for the next guy.