So I've been digging into the dash this morning to figure out why my mode lever doesn't work on my '79 . . . And it unfortunately looks like some of the linkage and rods are missing? What I'm seeing on the driver's side of the heater unit doesn't match the diagrams I have in the Hayne's and FSM.

If that's the case, is it possible to buy just the linkage parts I need? Or will I need to replace the entire heater assembly ( )? Once my camera is charged up I'll try and get a picture of what's going on under there.

 

Indeed it's possible to buy the links... check out your local junk yard. www.car-parts.com

 

Car-parts doesn't list the linkage separately . . . but it'll be good for getting contact info on junkyards with zx's in them.

Here's a picture of what's going on:


That spot just above the spring, is that where something's been snapped off? It feels like it, although it could just be a mark from the plastic mold. Hard to tell without a basis of comparison, the diagrams in the manuals aren't detailed enough to really figure it out.

 

Looks fine to me....

I'm not sure where you are looking in the Haynes / FSM, but there are detailed pics....

 

Page BE-42 in the service manual - same picture is on page 208 of the Haynes. I'm missing most of that stuff . . .

 

Everything looks normal to me, and I have ripped it all out before (had to clean... smelled musty). All the doors/vents are controlled by vacuum diaphragms. It's what gives them their smooth transitions instead of the hard mechanical linkage. Most likely you have a vacuum link. There is one hose that provides all the vacuum pressure (or technically lack of) for the vent controls. Check that. It should be the only vacuum hose going through your firewall.

Here is a pic off of a 80/81 Z I had the privileged to pillage at a junk yard. When I took mine apart, I couldn't figure out how all the vacuum hoses went back together, so I went to a junk yard and documented the correct way. Everything is correct in this picture, I used it to put mine back and it works fine.

 

What year is your car? What year is that manual?

You know about the FSM's on www.xenons130.com/reference ?

 

Huh. My manual is for a 79, which is the same year as the car. Matches up with the .pdf version. Any chance you recall whereabouts the main vacuum line goes through the firewall? I'll definitely check that.

I'm taking it down to get a VIN verification now, but will investigate more when I get back.

 

Dug into it some more this morning, it turns out there is a vacuum line broken, one of the ones on the passenger side that controls the side vent diaphragm. The one coming through the firewall looked perfect, until closer inspection revealed a small split all the way up where it attaches to the vacuum canister. Dunno if it's enough for a leak, but I'm off to Autozone to source some new line. It'll be a minor miracle if they actually have it in stock, the local store here is pretty incompetent.

Still vexed by the inconsistency in the manual's diagrams compared to what I see and what others are saying, but first things first, I suppose.

 

Wee! Fixed! Yeah, so that main vacuum line did the trick & got all the diaphragms working again. I still think it's crazy how different the service manual is from the actual in-car item - none of the control rods & linkages that are referenced in the manuals exist on my car. Quite the red herring for someone just starting to get to know these cars. Thanks for the help, everybody!

Anyway, it's interesting working on a car with more than 2 vacuum lines, and where a leak means more than just a surging idle.

 

It gets more complicated with a turbo. The intake manifold is not always under vacuum pressure!

 

Just a thought, but from that FSM pic you posted, you were looking in the "body electrical" section for info on the heater? It has basic electrically involved info there, but the main info is found in the "Heater and Air Conditioner" section. Look in that section (in both the FSM and Haynes) and you will find much more info.

 

All of the heater information is found in the body electrical chapter. A/C has it's own chapter, but doesn't address vents at all.